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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 IVKTLRe6YX9Kgtr1uk82d5xD1xW77ldwqFM3o89IJ5+trRqj844Ey9ak9TX2wung
 sBzlhBmoKcfchvCGZHwqeQ==

<SEC-DOCUMENT>0000902012-08-000053.txt : 20080808
<SEC-HEADER>0000902012-08-000053.hdr.sgml : 20080808
<ACCEPTANCE-DATETIME>20080808172453
ACCESSION NUMBER:		0000902012-08-000053
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080806
FILED AS OF DATE:		20080808
DATE AS OF CHANGE:		20080808

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MICROSOFT CORP
		CENTRAL INDEX KEY:			0000789019
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				911144442
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		ONE MICROSOFT WAY
		CITY:			REDMOND
		STATE:			WA
		ZIP:			98052-6399
		BUSINESS PHONE:		425-882-8080

	MAIL ADDRESS:	
		STREET 1:		ONE MICROSOFT WAY
		CITY:			REDMOND
		STATE:			WA
		ZIP:			98052-6399

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GATES WILLIAM H III
		CENTRAL INDEX KEY:			0000902012

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14278
		FILM NUMBER:		081003692

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		4258828080

	MAIL ADDRESS:	
		STREET 1:		ONE MICROSOFT WAY
		CITY:			REDMOND
		STATE:			WA
		ZIP:			98052
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-08-06</periodOfReport>

    <issuer>
        <issuerCik>0000789019</issuerCik>
        <issuerName>MICROSOFT CORP</issuerName>
        <issuerTradingSymbol>MSFT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000902012</rptOwnerCik>
            <rptOwnerName>GATES WILLIAM H III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE MICROSOFT WAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>REDMOND</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98052</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</value>
            </securityTitle>
            <transactionDate>
                <value>2008-08-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2000000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.9079</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>799130446</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed in multiple trades at prices ranging from $26.45 to $27.12.  The price reported above reflects the weighted average purchase price.  The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected.</footnote>
        <footnote id="F2">In addition, there are 424,816 shares owned by the reporting person's spouse.  The reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purposes.</footnote>
    </footnotes>

    <remarks>* Duly authorized under Special Power of Attorney appointing Michael Larson attorney-in-fact, dated February 3, 2006, by and on behalf of William H. Gates III, filed as Exhibit 99.1 to Cascade Investment, L.L.C.'s Amendment No. 2 to Schedule 13G with respect to Arch Capital Group Ltd. on March 7, 2006, SEC File No. 005-45257, and incorporated by reference herein.</remarks>

    <ownerSignature>
        <signatureName>William H. Gates III By: /s/ Michael Larson*, Attorney-In-Fact</signatureName>
        <signatureDate>2008-08-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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