Exhibit 99.1

FOR IMMEDIATE RELEASE Nasdaq: NSIT

INSIGHT ENTERPRISES, INC. REPORTS THIRD QUARTER
2010 RESULTS

TEMPE, Ariz. — November 3, 2010 — Insight Enterprises, Inc. (Nasdaq: NSIT) (the “Company”) today reported results of operations for the quarter ended September 30, 2010.

Third Quarter Highlights

For the third quarter of 2010 compared to the third quarter of 2009:

• Net sales increased 21% to $1.2 billion.

• Gross profit increased 16% to $154.6 million.

• Earnings from operations increased 109% to $24.8 million, or 2.1% of net sales.

• Net earnings from continuing operations increased 98% to $14.4 million.

• Diluted earnings per share from continuing operations increased 94% to $0.31.

“Today, we reported another quarter of healthy year over year growth driven by continued strong demand for IT products and improved execution,” stated Ken Lamneck, President and Chief Executive Officer. “We are executing better and maintaining our general cost disciplines while we invest strategically in our sales force, which should serve us well as we close out 2010 and head into 2011,” added Lamneck.

SEGMENT OVERVIEW

In North America, net sales were $871.2 million for the third quarter of 2010, up 27% from the third quarter of 2009. Net sales of hardware and software increased 34% and 25%, respectively, year over year, while net sales in the services category declined 14% year to year. Gross profit was up 18% year over year at $110.5 million with gross margin declining 90 basis points to 12.7% from 13.6% in the prior year quarter. Selling and administrative expenses in North America were $89.0 million during the third quarter of 2010, compared to $79.4 million in the third quarter of 2009. Selling and administrative expenses in the third quarter of 2010 did not include any significant professional fees and costs associated with the restatement remediation and related litigation. Comparatively, selling and administrative expenses in the third quarter of 2009 included $560,000 of such professional fees and costs. The North America segment recorded $199,000 of severance and restructuring expenses during the third quarter of 2010. Comparatively, during the third quarter of last year, North America recorded severance expense of $4.5 million, primarily related to the departure of the Company’s former President and Chief Executive Officer. As a result, earnings from operations in North America were $21.3 million, or 2.4% of net sales, in the third quarter of 2010, an increase of 125% from $9.5 million, or 1.4% of net sales, in the third quarter of 2009.

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

Insight Q3 2010 Results, Page 2 November 3, 2010

The Company’s EMEA operating segment reported net sales of $267.8 million for the third quarter of 2010, up 8% in U.S. dollars compared to the third quarter of 2009. Excluding the effects of foreign currency movements, net sales were up 16%. Net sales of hardware grew 1% year over year, software sales increased 12% and services sales grew by 33% compared to the third quarter of last year, all in U.S. dollars. Excluding the effects of foreign currency movements, hardware net sales increased 7%, software net sales increased 22% and services net sales increased 44% year over year. Gross profit was also up 8% in U.S. dollars, 16% excluding the effects of foreign currency movements, while gross margin remained relatively flat at 14.2% for the third quarter of 2010 compared to 14.3% in the prior year quarter. Selling and administrative expenses in EMEA in the third quarter of 2010 were up 4%, or $1.4 million, compared to the third quarter of 2009 in U.S. dollars and, excluding the effects of foreign currency movements, were up 13% year over year. EMEA also recorded $99,000 in severance and restructuring expenses, net of adjustments, in the quarter ended September 30, 2010, compared to a reduction of severance and restructuring expenses of $463,000 recorded during the third quarter of 2009. As a result, earnings from operations in EMEA were $2.2 million, or 0.8% of net sales, in the third quarter of 2010, an increase of 51% from $1.5 million, or 0.6% of net sales, in the third quarter of 2009.

The Company’s APAC operating segment reported net sales of $33.2 million for the third quarter of 2010, down 6% from the third quarter of 2009 in U.S. dollars, 13% excluding the effects of foreign currency movements. Gross profit was $6.0 million, an increase of 25% year over year in U.S. dollars, 18% excluding the effects of foreign currency movements, while gross margin increased to 18.0% for the third quarter of 2010 from 13.4% in the prior year quarter. Selling and administrative expenses in APAC increased 21% year over year in U.S. dollars, 13% excluding the effects of foreign currency movements. The APAC segment recorded no severance and restructuring charges during the quarter ended September 30, 2010, compared to a reduction of severance and restructuring expenses of $11,000 recorded during the third quarter of 2009. As a result, earnings from operations in APAC were $1.3 million, or 3.9% of net sales, in the third quarter of 2010, compared to $912,000, or 2.6% of net sales, in the third quarter of 2009.

UPDATED GUIDANCE

Given continued strong demand for hardware and software products, partially offset by a decline in services sales, the Company expects that diluted earnings per share will be between $0.38 and $0.43 in the fourth quarter.

CONFERENCE CALL AND WEBCAST

The Company will host a conference call and live web cast today at 5:00 p.m. ET to discuss third quarter 2010 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 1-800-706-7745 if located in the U.S., 617-614-3472 for international callers, and enter the access code 68365529.

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

Insight Q3 2010 Results, Page 3 November 3, 2010

Financial Summary Table
(dollars in thousands, except per share data)

	Three Months Ended September 30,							Nine Months Ended September 30,
Insight Enterprises, Inc.	2010		2009		% change			2010		2009		% change
Net sales	$	1,172,227	$	969,935		21	%	$	3,499,225	$	2,958,257		18	%
Gross profit	$	154,645	$	133,486		16	%	$	473,495	$	413,102		15	%
Earnings from operations	$	24,836	$	11,869		109	%	$	86,756	$	25,800		236	%
Net earnings from continuing operations	$	14,432	$	7,272		98	%	$	50,511	$	13,368		278	%
Diluted EPS from continuing operations	$	0.31	$	0.16		94	%	$	1.08	$	0.29		272	%
North America
Net sales	$	871,204	$	685,996		27	%	$	2,424,999	$	2,059,628		18	%
Gross profit	$	110,536	$	93,301		18	%	$	329,107	$	286,092		15	%
Earnings from operations	$	21,325	$	9,479		125	%	$	67,724	$	15,324		342	%
EMEA
Net sales	$	267,813	$	248,437		8	%	$	944,316	$	800,403		18	%
Gross profit	$	38,132	$	35,417		8	%	$	125,876	$	113,094		11	%
Earnings from operations	$	2,225	$	1,478		51	%	$	14,633	$	8,118		80	%
APAC
Net sales	$	33,210	$	35,502		(6	%)	$	129,910	$	98,226		32	%
Gross profit	$	5,977	$	4,768		25	%	$	18,512	$	13,916		33	%
Earnings from operations	$	1,286	$	912		41	%	$	4,399	$	2,358		87	%

	North America									EMEA									APAC
	Three Months Ended									Three Months Ended									Three Months Ended
	September 30,									September 30,									September 30,
Sales Mix	2010			2009			% change*			2010			2009			% change*			2010			2009			% change*
Hardware		66	%		62	%		34	%		38	%		41	%		1	%		1	%		< 1	%		157	%
Software		28	%		29	%		25	%		60	%		58	%		12	%		97	%		98	%		(7	%)
Services		6	%		9	%		(14	%)		2	%		1	%		33	%		2	%		2	%		(11	%)
		100	%		100	%		27	%		100	%		100	%		8	%		100	%		100	%		(6	%)

* Represents growth/decline in category net sales on a dollar basis.

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

Insight Q3 2010 Results, Page 4 November 3, 2010

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 estimated diluted earnings per share for the fourth quarter of 2010, the Company’s effective tax rate for 2010 and assumptions related to demand for hardware and software products and expectations of a decline in services sales for the full year 2010, 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 statement. 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, 2009:

• the Company’s reliance on partners for product availability, marketing funds, purchasing incentives and competitive products to sell;

• changes in the information technology industry and/or rapid changes in product standards;

• general economic conditions, including concerns regarding the Company’s ability to collect its accounts receivable and credit constraints;

• disruptions in the Company’s information technology systems and voice and data networks, including its system upgrade and the migration of acquired businesses to its information technology systems and voice and data networks;

• actions of the Company’s competitors, including manufacturers and publishers of products it sells;

• stockholder litigation and regulatory proceedings related to the restatement of the Company’s consolidated financial statements;

• the integration and operation of acquired businesses, including the Company’s ability to achieve expected benefits of the acquisitions;

• the variability and seasonality of the Company’s net sales and gross profit;

• the risks associated with international operations;

• exposure to changes in, or interpretations of, tax rules and regulations;

• exposure to foreign currency exchange risks;

• changes in the overall capital markets that could increase the Company’s borrowing costs or reduce future availability of financing;

• failure to comply with the terms and conditions of the Company’s public sector contracts;

• the Company’s dependence on key personnel; and

• intellectual property infringement claims and challenges to the Company’s registered trademarks and trade names.

Additionally, there may be other risks that are otherwise described from time to time in the reports that the Company files with the SEC. 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.

Contacts:	Glynis Bryan	Helen Johnson
	Chief Financial Officer	Senior VP, Treasurer
	Tel. 480-333-3390	Tel. 480-333-3234
	Email glynis.bryan@insight.com	Email helen.johnson@insight.com

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

Insight Q3 2010 Results, Page 5 November 3, 2010

INSIGHT ENTERPRISES, INC. AND SUBSIDIARIES
Consolidated Statements of Operations
(In thousands, except per share data)
(Unaudited)

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2010			2009			2010			2009
Net sales	$	1,172,227		$	969,935		$	3,499,225		$	2,958,257
Costs of goods sold		1,017,582			836,449			3,025,730			2,545,155
Gross profit		154,645			133,486			473,495			413,102
Operating expenses:
Selling and administrative expenses		129,511			117,623			385,052			374,831
Severance and restructuring expenses		298			3,994			1,687			12,471
Earnings from operations		24,836			11,869			86,756			25,800
Non-operating (income) expense:
Interest income		(161	)		(45	)		(467	)		(333	)
Interest expense		1,899			2,333			5,957			6,421
Net foreign currency exchange loss (gain)		130			93			743			(119	)
Other expense, net		348			217			1,097			697
Earnings from continuing operations before income taxes		22,620			9,271			79,426			19,134
Income tax expense		8,188			1,999			28,915			5,766
Net earnings from continuing operations		14,432			7,272			50,511			13,368
Net earnings from a discontinued operation		—			—			—			2,801
Net earnings	$	14,432		$	7,272		$	50,511		$	16,169
Net earnings per share — Basic:
Net earnings from continuing operations	$	0.31		$	0.16		$	1.09		$	0.29
Net earnings from a discontinued operation		—			—			—			0.06
Net earnings per share	$	0.31		$	0.16		$	1.09		$	0.35
Net earnings per share — Diluted:
Net earnings from continuing operations	$	0.31		$	0.16		$	1.08		$	0.29
Net earnings from a discontinued operation		—			—			—			0.06
Net earnings per share	$	0.31		$	0.16		$	1.08		$	0.35
Shares used in per share calculations:
Basic		46,268			45,875			46,193			45,812
Diluted		46,865			46,445			46,749			46,164

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

Insight Q3 2010 Results, Page 6 November 3, 2010

INSIGHT ENTERPRISES, INC. AND SUBSIDIARIES
Consolidated Balance Sheets
(In thousands)
(Unaudited)

	September 30,		December 31,
	2010		2009
ASSETS
Current assets:
Cash and cash equivalents	$	93,764	$	68,066
Accounts receivable, net		839,645		998,770
Inventories		122,685		77,694
Inventories not available for sale		30,296		47,722
Deferred income taxes		27,220		35,750
Other current assets		39,580		32,318
Total current assets		1,153,190		1,260,320
Property and equipment, net		142,973		150,103
Goodwill		16,474		15,829
Intangible assets, net		72,449		82,483
Deferred income taxes		73,950		78,489
Other assets		18,163		16,097
	$	1,477,199	$	1,603,321
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	563,327	$	695,549
Accrued expenses and other current liabilities		158,667		212,276
Current portion of long-term debt		992		875
Deferred revenue		39,874		54,135
Total current liabilities		762,860		962,835
Long-term debt		166,370		149,349
Deferred income taxes		2,729		3,054
Other liabilities		25,319		20,509
		957,278		1,135,747
Stockholders’ equity:
Preferred stock		—		—
Common stock		463		460
Additional paid-in capital		375,920		372,021
Retained earnings		124,375		73,864
Accumulated other comprehensive income — foreign currency translation adjustments		19,163		21,229
Total stockholders’ equity		519,921		467,574
	$	1,477,199	$	1,603,321

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

Insight Q3 2010 Results, Page 7 November 3, 2010

INSIGHT ENTERPRISES, INC. AND SUBSIDIARIES
Consolidated Statements of Cash Flows
(In thousands)
(Unaudited)

	Nine Months Ended September 30,
	2010			2009*
Cash flows from operating activities:
Net earnings	$	50,511		$	16,169
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization		28,515			29,074
Provision for losses on accounts receivable		546			2,795
Write-downs of inventories		4,875			5,623
Non-cash stock-based compensation		5,139			7,974
Non-cash gain from arbitrated claim, net of tax		—			(2,801	)
Excess tax benefit from employee gains on stock-based compensation		(912	)		—
Deferred income taxes		11,762			1,706
Changes in assets and liabilities:
Decrease in accounts receivable		143,709			281,677
(Increase) decrease in inventories		(32,676	)		12,836
(Increase) decrease in other current assets		(6,558	)		615
(Increase) decrease in other assets		(1,557	)		3,935
Decrease in accounts payable		(110,705	)		(215,022	)
(Decrease) increase in deferred revenue		(11,414	)		9,409
Decrease in accrued expenses and other liabilities		(43,727	)		(34,410	)
Net cash provided by operating activities		37,508			119,580
Cash flows from investing activities:
Acquisition of Calence, net of cash acquired		(5,123	)		(12,834	)
Purchases of property and equipment		(12,631	)		(11,739	)
Net cash used in investing activities		(17,754	)		(24,573	)
Cash flows from financing activities:
Borrowings on senior revolving credit facility		910,136			833,373
Repayments on senior revolving credit facility		(892,636	)		(905,873	)
Borrowings on accounts receivable securitization financing facility		45,000			165,000
Repayments on accounts receivable securitization financing facility		(45,000	)		(165,000	)
Payments on capital lease obligation		(681	)		(113	)
Net repayments under inventory financing facility		(9,952	)		(4,446	)
Payment of deferred financing fees		(490	)		(1,565	)
Proceeds from sales of common stock under employee stock plans		49			—
Excess tax benefit from employee gains on stock-based compensation		912			—
Payment of payroll taxes on stock-based compensation through shares withheld		(1,260	)		(463	)
Net cash provided by (used in) financing activities		6,078			(79,087	)
Foreign currency exchange effect on cash flows		(134	)		3,873
Increase in cash and cash equivalents		25,698			19,793
Cash and cash equivalents at beginning of period		68,066			49,175
Cash and cash equivalents at end of period	$	93,764		$	68,968

* Certain amounts in the consolidated statement of cash flows for the nine months ended September 30, 2009 have been reclassified to conform to the presentation for the nine months ended September 30, 2010.

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