Exhibit 99.1

INSIGHT ENTERPRISES, INC. REPORTS FOURTH QUARTER AND FULL YEAR 2012 RESULTS

TEMPE, AZ – February 14, 2013 – Insight Enterprises, Inc. (NASDAQ: NSIT) (the “Company”) today reported results of operations for the quarter and year ended December 31, 2012.

Fourth Quarter Highlights

For the fourth quarter of 2012 compared to the fourth quarter of 2011:

2012 Full Year Highlights

For the full year 2012 compared to the full year 2011:

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

During the fourth quarter of 2012, the Company’s effective tax rate was higher than normal due to a lower mix of income earned in foreign jurisdictions, which have a lower statutory tax rate, and valuation allowances recorded in certain countries in EMEA. During the fourth quarter of the prior year, the Company recorded a tax benefit from a reorganization of certain of its foreign operations, primarily related to the recognition of foreign tax credits, which decreased the Company’s effective tax rate.

“Overall, 2012 was a productive year for our business. Market conditions were softer as macro-economic concerns globally led to lower capital spending for IT products, but we executed well in the environment; improving the overall profitability of our sales, investing strategically in sales and services resources, successfully integrating two acquisitions, and essentially completing our IT systems integration projects in Europe and North America,” stated Ken Lamneck, President and Chief Executive Officer. “We believe these actions will position us well as we head through 2013,” added Lamneck.

SEGMENT OVERVIEW

In North America, net sales were $908.3 million for the fourth quarter of 2012, down 2% compared to sales of $922.5 million for the fourth quarter of 2011. Net sales of software increased 8% year over year, while net sales of hardware and services decreased 5% and 21%, respectively. Gross profit of $117.6 million was also down 2% year to year, with gross margin decreasing to 12.9% from 13.1% in the fourth quarter of 2011. Selling and administrative expenses in North America in the fourth quarter of 2012 remained flat, decreasing $166,000, compared to the fourth quarter of 2011. During the fourth quarter of 2012, North America had $535,000, $336,000 net of tax, of severance and restructuring expenses compared to $464,000, $285,000 net of tax, during the fourth quarter of 2011. As a result, earnings from operations in North America decreased 10% year to year to $27.5 million, or 3.0% of net sales, in the fourth quarter of 2012, compared to $30.4 million, or 3.3% of net sales, in the fourth quarter of 2011.

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

The Company’s EMEA operating segment reported net sales of $378.4 million for the fourth quarter of 2012, an increase of 2% in U.S. dollars compared to the fourth quarter of 2011. Excluding the effects of foreign currency movements, net sales increased 3% year over year. Results for the fourth quarter of 2012 include Inmac, which the Company acquired effective February 1, 2012. Net sales of hardware and services were up 24% and 37%, respectively, year over year, while net sales of software declined 7% year to year, all in U.S. dollars. Excluding the effects of foreign currency movements, hardware and services net sales increased 21% and 38%, respectively, while net sales of software declined 6% compared to the fourth quarter of 2011. Gross profit of $50.9 million was up 4% in U.S. dollars, also 4% excluding the effects of foreign currency movements, with gross margin increasing to 13.4% for the fourth quarter of 2012 from 13.2% in the fourth quarter of 2011. Selling and administrative expenses in EMEA in the fourth quarter of 2012 were up 13%, or $5.3 million, compared to the fourth quarter of 2011 in U.S. dollars and, excluding the effects of foreign currency movements, were up 14% year over year. During the fourth quarter of 2012, EMEA recorded severance and restructuring expenses of $1.3 million, $991,000 net of tax, compared to $163,000, $114,000 net of tax, reported for the fourth quarter of 2011. As a result, earnings from operations in EMEA decreased 53% year to year to $4.0 million, or 1.1% of net sales, in the fourth quarter of 2012 compared to $8.5 million, or 2.3% of net sales, in the fourth quarter of 2011.

The Company’s APAC operating segment reported net sales of $59.9 million for the fourth quarter of 2012, a decrease of 12% compared to the fourth quarter of 2011 in U.S. dollars, 15% excluding the effects of foreign currency movements. Gross profit was $12.0 million, an increase of 25% year over year in U.S. dollars, 21% excluding the effects of foreign currency movements, with gross margin increasing to 20.0% for the fourth quarter of 2012, an improvement of approximately 600 basis points compared to 14.0% in the fourth quarter of 2011. Selling and administrative expenses in APAC increased $653,000, or 11%, year over year in U.S. dollars, 8% excluding the effects of foreign currency movements. As a result, earnings from operations in APAC increased 52% year over year to $5.1 million, or 8.5% of net sales, in the fourth quarter of 2012 compared to $3.4 million, or 4.9% of net sales, in the fourth quarter of 2011.

Throughout this “Segment Overview” section, the Company refers to changes in net sales, gross profit and selling and administrative expenses in EMEA and APAC excluding the effects of foreign currency movements. In computing these changes and percentages, the Company compares the current year amount as translated into U.S. dollars under the applicable accounting standards to the prior year amount in local currency translated into U.S. dollars utilizing the average translation rate for the current period.

Net of tax amounts referenced above were computed using the statutory tax rate for the taxing jurisdictions in the operating segment in which the related expenses were recorded.

UPDATED GUIDANCE

For the full year of 2013, the Company expects the global IT market to grow in the low single digit range, with trends improving throughout the year. The Company expects its business to grow slightly faster than the market as it continues to invest in its sales force and expand its capabilities into key markets. For the full year of 2013, the Company expects diluted earnings per share to be between $2.22 and $2.32.

This outlook includes:

This outlook excludes severance and restructuring expenses.

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

CONFERENCE CALL AND WEBCAST

The Company will host a conference call and live web cast today at 5:00 p.m. ET to discuss fourth quarter and full year 2012 results of operations. A live web cast of the conference call (in listen-only mode) will be available on the Company’s web site at www.insight.com, and a replay of the web cast will be available on the Company’s web site for a limited time following the call. To listen to the live web cast by telephone, call 1-877-402-8904 if located in the U.S., 678-809-1029 for international callers, and enter the access code 92525863.

USE OF NON-GAAP FINANCIAL MEASURES

The non-GAAP financial measures exclude severance and restructuring expenses in 2012 and 2011, a gain on bargain purchase in 2012, and the tax effect of these items, as well as a tax benefit from a reorganization of certain foreign operations in 2011. The Company excludes these charges when internally evaluating earnings from operations, tax expense, net earnings and diluted earnings per share for the Company and earnings from operations for each of the Company’s operating segments. These non-GAAP measures are used to evaluate financial performance against budgeted amounts, to calculate incentive compensation, to assist in forecasting future performance and to compare the Company’s results to those of the Company’s competitors. The Company believes that these non-GAAP financial measures are useful to investors because they allow for greater transparency, facilitate comparisons to prior periods and the Company’s competitors’ results and assist in forecasting performance for future periods. These non-GAAP financial measures are not prepared in accordance with GAAP and may be different from non-GAAP financial measures presented by other companies. Non-GAAP financial measures should not be considered as a substitute for, or superior to, measures of financial performance prepared in accordance with GAAP.

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

FINANCIAL SUMMARY TABLE

(DOLLARS IN THOUSANDS, EXCEPT PER SHARE DATA)

(UNAUDITED)

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

FORWARD-LOOKING INFORMATION

Certain statements in this release and the related conference call and web cast are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements, including the Company’s expectations for growth in the global information technology (“IT”) market and the Company’s business and the Company’s expected 2013 diluted earnings per share, and the assumptions relating thereto, are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Future events and actual results could differ materially from those set forth in, contemplated by, or underlying the forward-looking statements. There can be no assurances that the results discussed by the forward-looking statements will be achieved, and actual results may differ materially from those set forth in the forward-looking statements. Some of the important factors that could cause the Company’s actual results to differ materially from those projected in any forward-looking statements, include, but are not limited to, the following, which are discussed in “Risk Factors” in Part I, Item 1A of the Company’s Annual Report on Form 10-K for the year ended December 31, 2011:

Additionally, there may be other risks that are otherwise described from time to time in the reports that the Company files with the Securities and Exchange Commission. Any forward-looking statements in this release should be considered in light of various important factors, including the risks and uncertainties listed above, as well as others. The Company assumes no obligation to update, and does not intend to update, any forward-looking statements. The Company does not endorse any projections regarding future performance made by third parties.

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

INSIGHT ENTERPRISES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF OPERATIONS

(IN THOUSANDS, EXCEPT PER SHARE DATA)

(UNAUDITED)

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

INSIGHT ENTERPRISES, INC. AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

(IN THOUSANDS)

(UNAUDITED)

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

INSIGHT ENTERPRISES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS

(IN THOUSANDS)

(UNAUDITED)

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958

INSIGHT ENTERPRISES, INC. AND SUBSIDIARIES

RECONCILIATION OF GAAP TO NON-GAAP FINANCIAL MEASURES

(IN THOUSANDS, EXCEPT PER SHARE DATA)

(UNAUDITED)

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Insight Enterprises, Inc.          6820 South Harl Avenue          Tempe, Arizona 85283          480-902-1001          FAX 480-760-8958