FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person *   FINNEGAN PAUL J 2. Date of Event Requiring Statement (Month/Day/Year) 06/26/2013 3. Issuer Name and Ticker or Trading Symbol CDW Corp [CDW] (Last) (First) (Middle) C/O MADISON DEARBORN PARTNERS, LLC, 70 W. MADISON STREET, SUITE 4600 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) CHICAGO, IL 60602 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock, par value $0.01 66,739,156 I See Footnotes (1) (2) (3)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
FINNEGAN PAUL J C/O MADISON DEARBORN PARTNERS, LLC 70 W. MADISON STREET, SUITE 4600 CHICAGO, IL 60602	  X	  X	Â	Â

Signatures

/s/ James S. Rowe, Attorney-in-Fact		06/26/2013
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Consists of 43,565,137shares held directly by Madison Dearborn Capital Partners V-A, L.P. ("MDP A"), 11,557,077 shares held directly by Madison Dearborn Capital Partners V-C, L.P. ("MDP C"), 437,743 shares held directly by Madison Dearborn Capital Partners V Executive-A, L.P. ("MDP Exec") and 11,179,199 shares held directly by MDCP Co-Investor (CDW), L.P. ("MDP Co-Investor"). Madison Dearborn Partners V-A&C, L.P. ('MDP V') is the general partner of MDP A, MDP C, MDP Exec and MDP Co-Investor. Madison Dearborn Partners, LLC ('MDP') is the general partner of MDP V.
(2)	As the sole members of a limited partner committee of MDP V that has the power, acting by majority vote, to vote or dispose of the shares directly held by MDP A, MDP C, MDP Exec and MDP Co-Investor, Paul J. Finnegan and Samuel M. Mencoff may be deemed to have shared voting and investment power over such shares. Each of Messrs. Finnegan and Mencoff and MDP V hereby disclaims any beneficial ownership of any shares held by MDP A, MDP C, MDP Exec and MDP Co-Investor except to the extent of his pecuniary interest therein.
(3)	The record and other beneficial owners of the reported securities have separately filed Form 3's.
  Remarks: Exhibit List:  Exhibit 24 - Power of Attorney

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