-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 VjpPg0feiAfc+TL4QFuwFA==

<SEC-DOCUMENT>0000921895-08-001459.txt : 20080516
<SEC-HEADER>0000921895-08-001459.hdr.sgml : 20080516
<ACCEPTANCE-DATETIME>20080516171717
ACCESSION NUMBER:		0000921895-08-001459
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080514
FILED AS OF DATE:		20080516
DATE AS OF CHANGE:		20080516

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ADAPTEC INC
		CENTRAL INDEX KEY:			0000709804
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER COMMUNICATIONS EQUIPMENT [3576]
		IRS NUMBER:				942748530
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		691 S MILPITAS BLVD
		STREET 2:		M/S25
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035
		BUSINESS PHONE:		4089458600

	MAIL ADDRESS:	
		STREET 1:		691 SOUTH MILPITAS BLVD
		STREET 2:		M/S25
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			STEEL PARTNERS II GP LLC
		CENTRAL INDEX KEY:			0001262861

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15071
		FILM NUMBER:		08843229

	BUSINESS ADDRESS:	
		STREET 1:		590 MADISON AVENUE, 32ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-758-3232

	MAIL ADDRESS:	
		STREET 1:		590 MADISON AVENUE, 32ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	STEEL PARTNERS LLC
		DATE OF NAME CHANGE:	20030908

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LICHTENSTEIN WARREN G
		CENTRAL INDEX KEY:			0001005784
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15071
		FILM NUMBER:		08843230

	BUSINESS ADDRESS:	
		STREET 1:		C/O STEEL PARTNERS L P
		STREET 2:		32ND FLOOR 590 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-758-3232

	MAIL ADDRESS:	
		STREET 1:		C/O STEEL PARTNERS II L P
		STREET 2:		590 MADISON AVENUE, 32ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Steel Partners II Master Fund L.P.
		CENTRAL INDEX KEY:			0001422280

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15071
		FILM NUMBER:		08843231

	BUSINESS ADDRESS:	
		STREET 1:		C/O MORGAN STANLEY FND SVCS LTD (CAYMAN)
		STREET 2:		CRICKET SQ 2ND FL HUTCHINS DR PO BX 2681
		CITY:			GRAND CAYMAN
		STATE:			E9
		ZIP:			KY1-1111
		BUSINESS PHONE:		212-520-2300

	MAIL ADDRESS:	
		STREET 1:		C/O MORGAN STANLEY FND SVCS LTD (CAYMAN)
		STREET 2:		CRICKET SQ 2ND FL HUTCHINS DR PO BX 2681
		CITY:			GRAND CAYMAN
		STATE:			E9
		ZIP:			KY1-1111

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			STEEL PARTNERS II LP
		CENTRAL INDEX KEY:			0000915653

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15071
		FILM NUMBER:		08843232

	BUSINESS ADDRESS:	
		STREET 1:		590 MADISON AVENUE
		STREET 2:		32ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-758-3232

	MAIL ADDRESS:	
		STREET 1:		590 MADISON AVENUE, 32ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	STEEL PARTNERS II L P
		DATE OF NAME CHANGE:	19950627

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Steel Partners LLC
		CENTRAL INDEX KEY:			0001422282

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15071
		FILM NUMBER:		08843233

	BUSINESS ADDRESS:	
		STREET 1:		590 MADISON AVENUE, 32ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-520-2300

	MAIL ADDRESS:	
		STREET 1:		590 MADISON AVENUE, 32ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ste55.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-05-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000709804</issuerCik>
        <issuerName>ADAPTEC INC</issuerName>
        <issuerTradingSymbol>ADPT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000915653</rptOwnerCik>
            <rptOwnerName>STEEL PARTNERS II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>590 MADISON AVENUE, 32ND FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001422282</rptOwnerCik>
            <rptOwnerName>Steel Partners LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O STEEL PARTNERS II, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>590 MADISON AVENUE, 32ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001005784</rptOwnerCik>
            <rptOwnerName>LICHTENSTEIN WARREN G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O STEEL PARTNERS II, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>590 MADISON AVENUE, 32ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001262861</rptOwnerCik>
            <rptOwnerName>STEEL PARTNERS II GP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O STEEL PARTNERS II, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>590 MADISON AVENUE, 32ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001422280</rptOwnerCik>
            <rptOwnerName>Steel Partners II Master Fund L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MORGAN STANLEY FUND SERVICES LTD</rptOwnerStreet1>
            <rptOwnerStreet2>CRICKET SQ FL2 BOUNDARY HALL HUTCHINS DR</rptOwnerStreet2>
            <rptOwnerCity>BOX 2681 GRAND CAYMAN KY1-1111</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $.001 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>22767</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.9754</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18565905</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $.001 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.9800</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18615905</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $.001 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>150000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.9967</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18765905</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $.001 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>100</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.9900</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18766005</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4 is filed jointly by Steel Partners II, L.P. (&quot;Steel Partners II&quot;), Steel Partners II GP LLC (&quot;Steel GP LLC&quot;), Steel Partners II Master Fund L.P. (&quot;Steel Master&quot;), Steel Partners LLC (&quot;Partners LLC&quot;) and Warren G. Lichtenstein. Steel GP LLC, Steel Master, Partners LLC and Mr. Lichtenstein may be deemed to be 10% owners of the Issuer and Steel Partners II is a 10% owner of the Issuer.</footnote>
        <footnote id="F2">The securities reported in this Form 4 are owned directly by Steel Partners II, and owned indirectly by Steel GP LLC by virtue of it being the general partner of Steel Partners II and Steel Master, by Steel Master by virtue of it being the sole limited partner of Steel Partners II, by Partners LLC by virtue of it being the investment manager of Steel Partners II and Steel Master and by Mr. Lichtenstein by virtue of his position as the manager of Partners LLC and the managing member of Steel GP LLC. Steel GP LLC, Steel Master, Partners LLC and Mr. Lichtenstein disclaim beneficial ownership of the shares owned by Steel Partners II except to the extent of their pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Steel Partners II, L.P., By: Steel Partners II GP LLC, General Partner, By: /s/ Lauren Isenman, as Attorney in Fact for Warren G. Lichtenstein, Managing Member</signatureName>
        <signatureDate>2008-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>By: Steel Partners LLC, By: /s/ Lauren Isenman, as Attorney In Fact for Warren G. Lichtenstein, Manager</signatureName>
        <signatureDate>2008-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>By: /s/ Lauren Isenman, as Attorney in Fact for Warren G. Lichtenstein</signatureName>
        <signatureDate>2008-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>By: Steel Partners II GP LLC, By: /s/ Lauren Isenman, as Attorney In Fact for Warren G. Lichtenstein, Managing Member</signatureName>
        <signatureDate>2008-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>By: Steel Partners II Master Fund L.P., By: Steel Partners II GP LLC, General Partner, By: /s/ Lauren Isenman, as Attorney In Fact for Warren G. Lichtenstein, Managing Member</signatureName>
        <signatureDate>2008-05-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----