-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000899171-07-000049.txt : 20071016
<SEC-HEADER>0000899171-07-000049.hdr.sgml : 20071016
<ACCEPTANCE-DATETIME>20071016141700
ACCESSION NUMBER:		0000899171-07-000049
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071012
FILED AS OF DATE:		20071016
DATE AS OF CHANGE:		20071016

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			COWELL CASEY
		CENTRAL INDEX KEY:			0001158157

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21796
		FILM NUMBER:		071173890

	BUSINESS ADDRESS:	
		STREET 1:		3000 RESEARCH DRIVE
		CITY:			RICHARDSON
		STATE:			TX
		ZIP:			75802

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CDW CORP
		CENTRAL INDEX KEY:			0000899171
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-CATALOG & MAIL-ORDER HOUSES [5961]
		IRS NUMBER:				363310735
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 N MILWAUKEE AVE
		CITY:			VERNON HILLS
		STATE:			IL
		ZIP:			60061
		BUSINESS PHONE:		8474656000

	MAIL ADDRESS:	
		STREET 1:		200 N MILWAUKEE AVE
		CITY:			VERNON HILLS
		STATE:			IL
		ZIP:			60061

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CDW COMPUTER CENTERS INC
		DATE OF NAME CHANGE:	19930322
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-10-12</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000899171</issuerCik>
        <issuerName>CDW CORP</issuerName>
        <issuerTradingSymbol>CDWC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001158157</rptOwnerCik>
            <rptOwnerName>COWELL CASEY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 NORTH MILWAUKEE AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>VERNON HILLS</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60061</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $.01 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2007-10-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>130166</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>87.75</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
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                <value>Common stock, $.01 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2007-10-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
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            <transactionAmounts>
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                <transactionPricePerShare>
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            <ownershipNature>
                <directOrIndirectOwnership>
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                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>MKW Partners, L.P.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>34.515</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-10-12</value>
            </transactionDate>
            <transactionCoding>
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            <transactionAmounts>
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                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
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            <exerciseDate>
                <value>2007-10-12</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2010-01-03</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                <underlyingSecurityShares>
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                <sharesOwnedFollowingTransaction>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
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            <conversionOrExercisePrice>
                <value>26.81</value>
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            <transactionDate>
                <value>2007-10-12</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>19800</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
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                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-10-12</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2011-01-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock, $.01 par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>19800</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>52.98</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-10-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>11044</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-10-12</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2012-05-22</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock, $.01 par value</value>
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                <underlyingSecurityShares>
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            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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            <ownershipNature>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>39.50</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-10-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>11425</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
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                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-10-12</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-05-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock, $.01 par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
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                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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                <natureOfOwnership>
                    <value></value>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>63.78</value>
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            <transactionDate>
                <value>2007-10-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>4542</value>
                </transactionShares>
                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
                    <value>D</value>
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            <exerciseDate>
                <value>2007-10-12</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2014-05-20</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                    <value>0</value>
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        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
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            <conversionOrExercisePrice>
                <value>58.44</value>
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            <transactionDate>
                <value>2007-10-12</value>
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            <transactionCoding>
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                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
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                <transactionPricePerShare>
                    <value>0</value>
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                <transactionAcquiredDisposedCode>
                    <value>D</value>
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            <exerciseDate>
                <value>2007-10-12</value>
                <footnoteId id="F2"/>
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            <expirationDate>
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            <underlyingSecurity>
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            <securityTitle>
                <value>Stock Options (Right to buy)</value>
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                <value>55.40</value>
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                <value>2007-10-12</value>
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                <transactionFormType>4</transactionFormType>
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                <transactionShares>
                    <value>5462</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <value>2007-10-12</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2016-05-17</value>
            </expirationDate>
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                <underlyingSecurityTitle>
                    <value>Common stock, $.01 par value</value>
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                    <value>0</value>
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                <directOrIndirectOwnership>
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                <natureOfOwnership>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to the acquisition of CDW Corporation by an entity controlled by investment funds affiliated with Madison Dearborn Partners, LLC and Providence Equity Partners, Inc. effective October 12, 2007, the stockholder received $87.75 in cash for each outstanding share of common stock.</footnote>
        <footnote id="F2">Pursuant to the acquisition of CDW Corporation by an entity controlled by investment funds affiliated with Madison Dearborn Partners, LLC and Providence Equity Partners, Inc. effective October 12, 2007, each stock option, regardless of whether it was exercisable upon completion of the merger, was cancelled by CDW Corporation and the holder of the stock option received a cash payment equal to the difference between the merger price of $87.75 and the exercise price of the option, times the number of shares subject to the stock option, less applicable withholding taxes.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Robert J. Welyki, Attorney-in-fact</signatureName>
        <signatureDate>2007-10-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
