Exhibit 99.4

3355 Michelson Drive, Suite 100

IRVINE, CA 92612

VOTE BY INTERNET – www.proxyvote.com or scan the QR Barcode above

Use the Internet to transmit your voting instructions up until 11:59 P.M. (Eastern Time in the U.S.) on the day immediately preceding the meeting date. Have your proxy card in hand when you access the web site and follow the instructions to obtain your records and to create an electronic voting instruction form.

VOTE BY PHONE – 1-800-690-6903

Use any touch-tone telephone to transmit your voting instructions up until 11:59 P.M. (Eastern Time in the U.S.) on the day immediately preceding the meeting date.*Have your proxy card in hand when you call and then follow the instructions.

VOTE BY MAIL

Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. Your proxy card must be received by 11:59 P.M. (Eastern Time in the U.S.) on the day immediately preceding the meeting date.*

*Participants in the Western Digital Corporation 401(k) Plan must provide voting instructions for the shares in their plan account by 11:59 P.M. Eastern Time on [•], 2016 to allow sufficient time for the plan trustee to vote the shares on your behalf.

TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS:	KEEP THIS PORTION FOR YOUR RECORDS
— — — — — — — — — — — — — — —  — — — — — — — — — — — — — — — — — — — —  — — — — — — — —

    THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. DETACH AND RETURN THIS PORTION ONLY

WESTERN DIGITAL CORPORATION
	The Board of Directors recommends you vote FOR the following:	For	Against	Abstain
1.	To approve the issuance of Western Digital Corporation (“Western Digital”) common stock in connection with the merger of Schrader Acquisition Corporation with and into SanDisk Corporation (“SanDisk”) with SanDisk continuing as the surviving corporation and as a direct wholly owned subsidiary of Western Digital Technologies, Inc., which is a wholly owned subsidiary of Western Digital, to the extent such issuance would require approval under NASDAQ Stock Market Rule 5635(a) (the “NASDAQ Stock Issuance Proposal”).	¨	¨	¨
2.	To approve adjournments of the Western Digital special meeting, if necessary or appropriate, including to permit further solicitation of proxies if there are not sufficient votes at the time of the Western Digital special meeting to approve the NASDAQ Stock Issuance Proposal.	¨	¨	¨
3.	To approve, by non-binding, advisory vote, compensation that will or may be paid or become payable by Western Digital to one of its named executive officers, in connection with the Merger.	¨	¨	¨
Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Joint owners should each sign personally. All holders must sign. If a corporation or partnership, please sign in full corporate or partnership name by authorized officer.

Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date

— — — — — — — — — — — — —  — — — — — — — — — — — — — — — — — — — —  — — — — — — — — — —

Solicited on Behalf of the Board of Directors of

WESTERN DIGITAL CORPORATION

FOR THE

SPECIAL MEETING OF SHAREHOLDERS [●], 2016, [●] LOCAL TIME

The undersigned, revoking all other proxies heretofore given, hereby acknowledges receipt of the joint proxy statement/prospectus and hereby appoints Michael C. Ray and Matthew E. Massengill, or either of them, as proxies, each with the power to appoint (his/her) substitute, and hereby authorizes them to represent and to vote, as designated on the reverse side of this ballot, all of the shares of Common stock of WESTERN DIGITAL CORPORATION which the undersigned is entitled to vote at the Special Meeting of Shareholders of Western Digital Corporation, to be held on [●], [●], 2016 at [●], local time, at [●] and any adjournments or postponements thereof. You may vote at the Special Meeting if you were a shareholder of record at the close of business on [●].

This proxy, when properly executed, will be voted in the manner directed herein by the undersigned shareholder. If no such direction is made, this proxy will be voted in accordance with the Board of Directors’ recommendations. If other matters are properly brought before the Special Meeting, including an adjournment of the Special Meeting for any reason other than the ones specified in the adjournment proposal on the reverse side of this ballot, the proxies are hereby authorized to represent and to vote or act on those matters according to their best judgment.

If you are one of Western Digital Corporation’s employees or former employees who participates in the Western Digital Common Stock Fund under the Western Digital 401(k) Plan, then this card also constitutes your voting instructions to T. Rowe Price Company, the plan trustee. If you do not submit voting instructions for your plan shares, such shares will be voted by T. Rowe Price Company in the same proportion as the other shares in the Western Digital Corporation Common Stock Fund are affirmatively voted by plan participants.

To be Signed on Reverse Side