Exhibit 10.2

VOTING AGREEMENT

VOTING AGREEMENT, dated as of March 8, 2012 (this “Agreement”), among Quest Software, Inc., a Delaware corporation (the “Company”), and Vincent Smith (the “Executive”), the Vincent C. Smith Annuity Trust 2010-1, the Vincent C. Smith Annuity Trust 2010-2 and the Vincent C. Smith Annuity Trust 2011-1 (each a “Stockholder” and collectively, the “Stockholders”).

RECITALS

WHEREAS, the Company, Expedition Holding Company, Inc. (“Parent”) and Expedition Merger Sub, Inc. (“Merger Sub”) propose to enter into an Agreement and Plan of Merger dated as of the date hereof in the form attached hereto (the “Merger Agreement”; capitalized terms used but not defined herein shall have the meanings set forth in the Merger Agreement as entered into on the date hereof) providing for the merger of Merger Sub with and into the Company (the “Merger”), upon the terms and subject to the conditions set forth in the Merger Agreement;

WHEREAS, as of the date hereof, the Stockholders are the record and/or beneficial owner of the number of shares of the Company common stock set forth on Schedule A attached hereto and have the voting and dispositive power in connection with the Merger with respect to such shares as set forth on Schedule A attached hereto (with respect to the Stockholders, such Stockholders’ “Existing Shares” and, together with any shares of the Company common stock acquired after the date hereof, whether upon the exercise of warrants, options, conversion of convertible securities or otherwise, such Stockholders’ “Shares”); and

WHEREAS, as an inducement and a condition to entering into the Merger Agreement, the Company has required that the Stockholders agree, and the Stockholders have agreed, to enter into this Agreement.

NOW, THEREFORE, to implement the foregoing and in consideration of the mutual agreements contained herein, the parties agree as follows:

AGREEMENT

1. Agreement to Vote; Standstill.

(a) Subject to the terms and conditions hereof, each Stockholder hereby irrevocably and unconditionally agrees that, from and after the date hereof and until the Termination Date, at any meeting of the holders of Company common stock, however called, or in connection with any written consent of the holders of Company common stock, such Stockholder shall (x) appear at such meeting or otherwise cause all of such Stockholder’s Shares to be counted as present thereat for purposes of calculating a quorum and respond to any other request by the Company for written consent, if any, and (y) to the extent such Stockholder has the ability to do so as set forth on Schedule A attached hereto, vote (or cause to be voted) such Stockholder’s Shares (i) in favor of adoption and approval of the Merger Agreement and the Merger and the approval of the terms thereof and each of the other actions contemplated by the Merger Agreement and this Agreement and (ii) except as otherwise agreed to in writing in

advance by the Company, against the following actions (other than the Merger and the transactions contemplated by the Merger Agreement): (A) any Takeover Proposal (other than a Superior Proposal); (B) any other action involving the Company or its subsidiaries which has the effect of impeding, interfering with, delaying, postponing, or impairing (I) the ability of the Company to consummate the Merger on or prior to the Outside Date or (II) the Transactions or (C) any action or agreement that would reasonably be expected to result in any condition to the consummation of the Merger set forth in Article VI of the Merger Agreement not being fulfilled on or prior to the Outside Date. Each such Stockholder shall not enter into any agreement or understanding with any person or entity prior to the termination of this Agreement to vote in any manner inconsistent herewith. Except as set forth in this Section 1, such Stockholder shall not be restricted from voting in favor of, against or abstaining with respect to any matter presented to the stockholders of the Company.

(b) In furtherance of the agreements contained in Section 1(a) hereof, subject to the terms and conditions hereof, each Stockholder hereby agrees (a) to complete and send the proxy card received by such Stockholder with the Proxy Statement, so that such proxy card is received by the Company, as prescribed by the Proxy Statement, not later than the fifth Business Day preceding the day of the Company Stockholders Meeting, (b) to vote, by completing such proxy card but not otherwise, all the Shares he or it owns of record or beneficially as of the record date for the Company Stockholders Meeting (i) in favor of adoption and approval of the Merger Agreement and the Merger and (ii) if the opportunity to do so is presented to such Stockholder on the proxy card, against any action of the type set forth in clauses (A) through (C) of Section 1(a), and (c) not to revoke any such proxy until the Termination Date.

(c) Notwithstanding anything to the contrary in this Agreement, (i) nothing herein shall prevent any Stockholder from (A) engaging or entering into any unsolicited discussions, agreements, understandings or arrangements with any third Person regarding his or his Affiliates’ or its or its Affiliates’ direct or indirect equity participation, investment or reinvestment with respect to any Takeover Proposal, (B) if requested by the Board of Directors of the Company or the Special Committee, participating in a due diligence process with any third party with respect to any potential Takeover Proposal or (C) from complying with any agreement between the Executive and the Company with respect to his obligations to participate in the activities of the Company relation to the Go-Shop Period, in connection with a potential Takeover Proposal or any other matter relating to the actions which the Company may take during the Go-Shop Period, (ii) none of the provisions of this Agreement shall restrict the Executive from taking, or refraining from taking, any action solely in his capacity as director or officer of the Company; (iii) the obligations of the Stockholders set forth in Sections 1(a) and Section 1(b) shall not apply to any Takeover Proposal other than the Transactions as described in the Merger Agreement, whether or not such Takeover Proposal is deemed to be a Superior Proposal and (iv) the obligations of the Stockholders set forth herein are subject to the condition that the Merger Agreement not be amended, modified or waived by the parties thereto in any manner that could reasonably be expected to materially adversely impact the Stockholders, without the prior written consent of the Stockholders with respect to such amendment, modification or waiver.

(d) Standstill. Each Stockholder hereby irrevocably and unconditionally agrees that, from and after the date hereof and until the Termination Date, such Stockholder shall not, and shall cause its respective affiliates or representatives acting on behalf of such Stockholder in taking such actions not to, in any manner, directly or indirectly, effect or seek, offer or propose (whether publicly or otherwise) to effect or participate in, or announce any intention to effect, cause, participate in or in any way assist, facilitate or encourage any other person (other than the other Stockholders, the Equity Providers or the providers of Debt Financing in connection with the Transactions) to effect or seek, offer or propose (whether publicly or otherwise) to effect or participate in any acquisition of any securities (or beneficial ownership thereof) or rights or options to acquire any securities (or beneficial ownership thereof) of the Company other than engaging in (i) the actions described in Section 1(c) during the Go-Shop Period, in such Stockholder’s capacity as a Stockholder, (ii) any actions permitted by the Company during the Go-Shop Period or not prohibited during the period commencing on the No-Shop Period Start Date, in the Executive’s capacity as a director or officer of the Company (iii) any disposition or transfer of the Shares by any Stockholder to any other Stockholder or to any member of the Executive’s immediate family (including his current or former spouse and their respective immediate families) or for estate planning purposes or (iv) any acquisition or exercise of options or other equity based compensation awarded to any Stockholder, pursuant to any option or equity based compensation adopted by the Board of Directors, in accordance with their respective terms and subject to applicable securities laws.

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2. Representations and Warranties of the Stockholders. Each Stockholder hereby represents and warrants to the Company, as of the date hereof, and at all times during the term of this Agreement, as follows:

(a) Authorization; Validity of Agreement; Necessary Action. Such Stockholder has full power and authority to execute and deliver this Agreement, to perform such Stockholder’s obligations hereunder and to consummate the transactions contemplated hereby. This Agreement has been duly executed and delivered by such Stockholder, and, assuming this Agreement constitutes a valid and binding obligation of the Company, constitutes a valid and binding obligation of such Stockholder, enforceable against such Stockholder in accordance with its terms, except that (i) such enforcement may be subject to applicable bankruptcy, insolvency or other similar laws, now or hereafter in effect, affecting creditors’ rights generally, and (ii) the remedy of specific performance and injunctive and other forms of equitable relief may be subject to equitable defenses and to the discretion of the court before which any proceeding therefor may be brought.

(b) Shares. Such Stockholder’s Existing Shares are owned beneficially and/or of record by such Stockholder, as set forth on Schedule A attached hereto. Such Stockholder’s Existing Shares constitute all of the shares of Company common stock owned of record or beneficially by such Stockholder, and, except for such Stockholder’s Existing Shares, such Stockholder does not beneficially own or have any right to acquire (whether currently, upon lapse of time, following the satisfaction of any conditions, upon the occurrence of any event or any combination of the foregoing) any Shares or any securities convertible into Shares (other than pursuant to any option, stock award or similar compensation plan adopted by the Company). Such Stockholder has the voting power, sole power of disposition, sole power to issue instructions with respect to the matters set forth in Section 1 hereof, sole power of conversion, sole power to demand appraisal rights and power to agree to all of the matters set forth in this Agreement with respect to each of such Stockholder’s Existing Shares as set forth on Schedule A attached hereto, with no other limitations, qualifications or restrictions on such rights, subject to applicable federal securities laws and the terms of this Agreement and the Merger Agreement. As to the Existing Shares held of record by such Stockholder, such Stockholder has good and valid title to such Existing Shares, free and clear of all liens, claims, security interests or other charges or encumbrances (other than such liens, claims, security interests or other charges or encumbrances, arising with respect to the financing agreements secured in part by pledges of shares of Company Common Stock owned by the Stockholders, each of each which shall be released substantially contemporaneously with the consummation of the Merger pursuant to the terms of the Financing Letters).

3. Representations and Warranties of the Company. The Company hereby represents and warrants to the Stockholders, as of the date hereof, and at all times during the term of this Agreement, as follows:

(a) Organization. The Company is a corporation duly organized, validly existing and in good standing under the laws of the jurisdiction of its incorporation.

(b) Corporate Authorization; Validity of Agreement; Necessary Action. The Company has full corporate power and authority to execute and deliver this Agreement and to

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consummate the transactions contemplated hereby. The execution, delivery and performance by the Company of this Agreement and the consummation by the Company of the transactions contemplated hereby have been duly and validly authorized by the Board of Directors of the Company, and no other corporate action or proceedings on the part of the Company are necessary to authorize the execution and delivery by the Company of this Agreement, and the consummation by the Company of the transactions contemplated hereby. This Agreement has been duly executed and delivered by the Company, and, assuming this Agreement constitutes a valid and binding obligation of the Stockholders, constitutes valid and binding obligations of the Company, enforceable against it in accordance with its terms, except that (i) such enforcement may be subject to applicable bankruptcy, insolvency or other similar laws, now or hereafter in effect, affecting creditors’ rights generally, and (ii) the remedy of specific performance and injunctive and other forms of equitable relief may be subject to equitable defenses and to the discretion of the court before which any proceeding therefor may be brought.

4. Further Assurances. From time to time, at any other party’s request and without further consideration, each party hereto shall execute and deliver such additional documents and take all such further lawful action as may be necessary or desirable to consummate and make effective, in the most expeditious manner practicable, the transactions contemplated by this Agreement.

5. Termination. This Agreement shall terminate, and no party shall have any rights or obligations hereunder and this Agreement shall become null and void and have no further effect upon the earlier of the (a) Effective Time, (b) termination of the Merger Agreement in accordance with its terms and (c) termination of the Rollover Letter in accordance with its terms (any such date shall be referred to herein as the “Termination Date”). Nothing in this Section 6 shall relieve any party of liability for breach of this Agreement.

6. Costs and Expenses. All costs and expenses incurred in connection with this Agreement and the consummation of the transactions contemplated hereby shall be paid by the party incurring such expenses.

7. Amendment and Modification. This Agreement may be amended, modified and supplemented in any and all respects only by written agreement executed and delivered by each of the respective parties. No provision of this Agreement may be waived, discharged or terminated other than by an instrument in writing signed by the party against whom the enforcement of such waiver, discharge or termination is sought, except that this Agreement may be terminated as set forth in Section 5.

8. Notices. All notices and other communications hereunder shall be in writing and shall be deemed given if delivered personally, telecopied (which is confirmed) or sent by an overnight courier service to the parties at the following addresses (or at such other address for a party as shall be specified by like notice):

(i) if to the Company, to:

Quest Software, Inc.

5 Polaris Way

Aliso Viejo, CA 92656

Attention: General Counsel

Facsimile: (949) 754-8799

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with a copy to:

Potter Anderson & Corroon LLP

1313 N. Market Street, 6^th Floor

Wilmington, DE 19801

Attention: Mark A. Morton

Facsimile: (302) 778-6078

Latham & Watkins LLP

650 Town Center Drive, 20^th Floor

Costa Mesa, CA 92626

Attention: Charles K. Ruck

Facsimile: (714) 755-8290

if to any Stockholder, to:

Vincent C. Smith

5 Polaris Way

Aliso Viejo, CA 92656

with a copy to:

Cadwalader, Wickersham & Taft LLP

One World Financial Center

New York, NY 10281

Attention: R. Ronald Hopkinson

Facsimile: (212) 504-6666

9. Interpretation. When a reference is made in this Agreement to Sections, such reference shall be to a Section of this Agreement unless otherwise indicated. Whenever the words “include”, “includes” or “including” are used in this Agreement they shall be deemed to be followed by the words “without limitation”.

10. Counterparts. This Agreement may be executed in any number of counterparts (including by facsimile), each such counterpart being deemed to be an original instrument, and all such counterparts shall together constitute the same agreement.

11. Entire Agreement; No Third Party Beneficiaries. This Agreement constitutes the entire agreement and supersedes all prior agreements and understandings, both written and oral, among the parties with respect to the subject matter hereof, including that certain Voting Agreement dated June 1, 2009 by and between the Company and Vincent Smith, and is not intended to confer upon any person other than the parties hereto any rights or remedies hereunder.

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12. Severability. The provisions of this Agreement shall be deemed severable and the invalidity or unenforceability of any provision shall not affect the validity or enforceability of the other provisions hereof. If any provision of this Agreement, or the application thereof to any person or any circumstance, is invalid or unenforceable, (a) a suitable and equitable provision shall be substituted therefor in order to carry out, so far as may be valid and enforceable, the intent and purpose of such invalid or unenforceable provision and (b) the remainder of this Agreement and the application of such provision to other persons or circumstances shall not be affected by such invalidity or unenforceability, nor shall such invalidity or unenforceability affect the validity or enforceability of such provision, or the application thereof, in any other jurisdiction.

13. Specific Performance; Remedies Cumulative. (a) The parties hereto agree that irreparable damage would occur in the event any provision of this Agreement was not performed in accordance with the terms hereof and that the parties shall be entitled to seek the remedy of specific performance of the terms hereof, in addition to any other remedy at law or equity.

(b) Remedies Cumulative. All rights, powers and remedies provided under this Agreement or otherwise available in respect hereof at law or in equity shall be cumulative and not alternative, and the exercise of any thereof by any party shall not preclude the simultaneous or later exercise of any other such right, power or remedy by such party.

14. Governing Law. This Agreement shall be governed and construed in accordance with the laws of the State of Delaware without giving effect to the principles of conflicts of law thereof.

15. Assignment. Neither this Agreement nor any of the rights, interests or obligations hereunder shall be assigned by any of the parties hereto (whether by operation of law or otherwise) without the prior written consent of the other parties. Subject to the preceding sentence, this Agreement will be binding upon, inure to the benefit of and be enforceable by the parties and their respective successors and assigns.

16. Consent to Jurisdiction; Waiver of Jury Trial. (a) Each of the parties hereto:

(i) consents to submit itself to the personal jurisdiction of the Chancery Courts of the State of Delaware and the Federal courts of the United States of America located in the State of Delaware in the event any dispute arises out of this Agreement or any of the transactions contemplated by this Agreement;

(ii) agrees that it will not attempt to deny or defeat such personal jurisdiction or venue by motion or other request for leave from any such court;

(iii) agrees that it will not bring any action relating to this Agreement or any of the transactions contemplated by this Agreement in any court other than such courts; and

(iv) agrees that service of process in any such action or proceeding may be effected by mailing a copy thereof by registered or certified mail (or any substantially similar form of mail), postage prepaid, to a party at its address set forth in Section 9 or at such other address of which a party shall have been notified pursuant thereto;

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(v) agrees that nothing herein shall affect the right to effect service of process in any other manner permitted by law or shall limit the right to sue in any other jurisdiction; and

(vi) agrees to appoint an agent for service of process in Delaware.

(b) EACH PARTY HERETO HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES TRIAL BY JURY IN ANY LEGAL ACTION OR PROCEEDING IN RELATION TO THIS AGREEMENT AND FOR ANY COUNTERCLAIM THEREIN.

17. Negotiated Terms. The provisions of this Agreement are the result of negotiations between the parties. Accordingly, this Agreement shall not be construed in favor of or against any party by reason of the extent to which the party or any of his or its professional advisors participated in its preparation.

18. Action in Stockholder Capacity Only. The parties acknowledge that this Agreement is entered into by each Stockholder solely in such Stockholder’s capacity as the record and/or beneficial owner of the Shares and nothing in this Agreement restricts or limits any action taken by the Executive in his capacity as a director or officer of the Company, or any of his controlled affiliates (but not on his own behalf as a Stockholder) and the taking of any actions (or failure to act) in his capacity as an officer or director of the Company, or any of his controlled affiliates will not be deemed to constitute a breach of this Agreement.

[Signature Page Follows]

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IN WITNESS WHEREOF, the Company and each of the Stockholders have caused this Agreement to be signed by their respective officers or other authorized person thereunto duly authorized as of the date first written above.

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SCHEDULE A

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