A quote from KB1005593
This article assumes that you have extracted the contents of the sysprep deploy.cab file to the directory C:\sysprep on the VirtualCenter Server host. You must substitute the actual directory in the instructions below.
Log in to the VirtualCenter Server as Administrator.
Click Start > Programs > Accessories > Windows Explorer.
Navigate to the C:\sysprep directory.
Right-click on the sysprep.exe file and choose Properties.
Click the Version tab. Record the number at the top next to "File Version:"
The following list is a copy from: KB1005593. The list is sorted on Windows version, Download link and vCenter location.
Windows 2000 Server SP4 with Update Rollup 1
http://www.microsoft.com/downloads/details.aspx?FamilyID=0c4bfb06-2824-4d2b-abc1-0e2223133afb
C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep\1.1
Windows XP Pro SP2
http://www.microsoft.com/downloads/details.aspx?FamilyId=3E90DC91-AC56-4665-949B-BEDA3080E0F6
C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep\xp
Windows 2003 Server SP1
http://www.microsoft.com/downloads/details.aspx?familyid=A34EDCF2-EBFD-4F99-BBC4-E93154C332D6
C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep\svr2003
Windows 2003 Server SP2
http://www.microsoft.com/downloads/details.aspx?FamilyID=93f20bb1-97aa-4356-8b43-9584b7e72556
C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep\svr2003
Windows 2003 Server R2
http://www.microsoft.com/downloads/details.aspx?familyid=A34EDCF2-EBFD-4F99-BBC4-E93154C332D6
C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep\svr2003
Windows 2003 x64
http://www.microsoft.com/downloads/details.aspx?familyid=C2684C95-6864-4091-BC9A-52AEC5491AF7&displaylang=en
C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep\svr2003-64
Windows XP x64
http://www.microsoft.com/downloads/details.aspx?familyid=C2684C95-6864-4091-BC9A-52AEC5491AF7&displaylang=en
C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep\xp-64