<SEC-DOCUMENT>0001266824-12-000137.txt : 20121226
<SEC-HEADER>0001266824-12-000137.hdr.sgml : 20121226
<ACCEPTANCE-DATETIME>20121226161751
ACCESSION NUMBER:		0001266824-12-000137
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20121221
FILED AS OF DATE:		20121226
DATE AS OF CHANGE:		20121226

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NICKL WOLFGANG U.
		CENTRAL INDEX KEY:			0001499701

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08703
		FILM NUMBER:		121285513

	MAIL ADDRESS:	
		STREET 1:		C/O WESTERN DIGITAL CORPORATION
		STREET 2:		3355 MICHELSON DRIVE, SUITE 100
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92612

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WESTERN DIGITAL CORP
		CENTRAL INDEX KEY:			0000106040
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER STORAGE DEVICES [3572]
		IRS NUMBER:				330956711
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0629

	BUSINESS ADDRESS:	
		STREET 1:		3355 MICHELSON DRIVE
		STREET 2:		SUITE 100
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92612
		BUSINESS PHONE:		9499325000

	MAIL ADDRESS:	
		STREET 1:		3355 MICHELSON DRIVE
		STREET 2:		SUITE 100
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92612

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GENERAL DIGITAL CORP
		DATE OF NAME CHANGE:	19730125
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-12-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000106040</issuerCik>
        <issuerName>WESTERN DIGITAL CORP</issuerName>
        <issuerTradingSymbol>WDC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001499701</rptOwnerCik>
            <rptOwnerName>NICKL WOLFGANG U.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WESTERN DIGITAL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>3355 MICHELSON DRIVE, SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>IRVINE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92612</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-12-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>26257</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>92009</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-12-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>31761</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>41.8534</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60248</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>16.85</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2012-12-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>26257</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-02-04</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2016-02-04</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>26257</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1750</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $41.82 to a high of $41.91. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F2">Includes 286 shares acquired under the issuer's Employee Stock Purchase Plan on November 30, 2012.</footnote>
        <footnote id="F3">The option vested 25% one year from the grant date of 2/4/2009, and an additional 6.25% vested at the end of each three-month period through 11/4/2012.  The remaining shares subject to the option will vest at 6.25% at the end of each three-month period until fully vested on 2/4/2013.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: /s/ Sandra Garcia Attorney-in-Fact  For: Wolfgang U. Nickl</signatureName>
        <signatureDate>2012-12-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
