EX-4.5



 Exhibit 4.5 
 THE WESTERN DIGITAL CORPORATION 401(K) PLAN 
 Effective upon the closing of the
transactions contemplated by that certain Stock Purchase Agreement, dated as of March 7, 2011, by and among Western Digital Corporation, Western Digital Ireland, Ltd., Hitachi, Ltd. and Viviti Technologies Ltd. (the “Effective Date”),
and except as otherwise specified herein, the Western Digital Corporation 401(k) Plan (hereinafter referred to as the “Plan”) is hereby amended as provided herein. 
 WHEREAS, Western Digital Corporation (hereinafter referred to as the “Employer”) heretofore adopted the Plan effective January 1, 2010; and 

WHEREAS, the Plan consists of the Accudraft Prototype Defined Contribution Retirement Plan, Basic Plan Number #01 (hereinafter referred to as the
“Basic Plan Document”) and the Accudraft 401(k) Non Standardized Prototype Adoption Agreement #002 (hereinafter referred to as the “Adoption Agreement”); and 
 WHEREAS, the Basic Plan Document provides that the Employer may change the choice of options in the Adoption Agreement at any time; and 
 WHEREAS, the Employer desires to change the options in the Adoption Agreement as provided herein; 

NOW, THEREFORE, the Plan is hereby amended as follows: 
 First Change 
 On the Effective Date, Section 2.2 of the Adoption Agreement,
Plan Data, is hereby deleted in its entirety and shall read as follows: 
 Predecessor Service.
x Service with the following entity or entities will be credited as selected in (a), (b), (c), (d) and (e) below: (this section need only be completed if the Employer
does not maintain the plan of the predecessor employer) 
 Adaptive Data Systems, Inc., Faraday Electronics, Inc., Paradise Systems,
Inc., Verticom, Inc., Atasi, Tandon Corporation, ViaNetix, Inc., Senvid, Inc., Komag, Inc., Silicon Systems, Inc. and HGST America. 
  

	(a)  x	Elective Deferrals, QMACs and QNECs. Service with an entity listed above will be given for eligibility purposes under Section 3.2(a) of the Adoption Agreement.


  

	(b)   ̈	ADP Safe Harbor Contributions. Service with an entity listed above will be given for eligibility purposes under Section 3.2(b) of the Adoption Agreement.


  

	(c)   ̈	ACP Safe Harbor Matching Contributions. Service with an entity listed above will be credited for: (check all that apply) 


 

	 	 ̈	Eligibility purposes under Section 3.2(c) of the Adoption Agreement 

  

	 	 ̈	Vesting purposes under Section 10.3 of the Adoption Agreement 

  

	(d)  x	Non-Safe Harbor Matching Contributions. Service with an entity listed above will be credited for: (check all that apply) 


 

	 	x	Eligibility purposes under Section 3.2(d) of the Adoption Agreement 

  

	 	x	Vesting purposes under Section 10.4 of the Adoption Agreement 









	(e)  x	Non-Safe Harbor Non-Elective Contributions. Service with an entity listed above will be credited for: (check all that apply) 


 

	 	x	Eligibility purposes under Section 3.2(e) of the Adoption Agreement 

  

	 	x	Vesting purposes under Section 10.5 of the Adoption Agreement 

 Second Chance 
 On the Effective Date, Section 8.1(c) of the Adoption
Agreement, Rollover Contributions, is hereby deleted in its entirety and shall read as follows: 
 (c) Rollover Contributions can
also include the following: (check all that apply) 
  

	 	 ̈	Roth Elective Deferrals (Note: Can be checked only if this Plan also permits Roth Elective Deferrals) 


 

	 	 ̈	Voluntary Employee Contributions 

  

	 	 ̈	Mandatory Employee Contributions 

  

	 	x	Participant loans (available for employees of HGST America only) 

  

	 	 ̈	In kind distributions (other than Participant loans) 

 In all other respects, the Plan is hereby ratified and affirmed. 
 IN WITNESS WHEREOF, and as
evidence of its adoption of this amendment to the Western Digital Corporation 401(k) Plan, the Employer has caused this document to be executed by its duly authorized officers. 

 

									
		 		 	Western Digital Corporation
					
	Witness:	 	/s/ Jason Bibelheimer	 		 	By:	 	/s/ Jackie Demaria
	Print Name: Jason Bibelheimer	 		 	Print Name: Jackie Demaria
		 		 		 	Title:	 	SVP, HR
		 		 		 	Date:	 	1/3/2012