As per
http://www.microsoft.com/exchange/en-us/system-requirements.aspx
Operating system—Microsoft Windows Server 2008 x64 Standard and Enterprise Edition with Service Pack 2 or Microsoft Windows Server 2008 R2 Standard and Enterprise Edition.
You cannot run Exchange Server on Windows Vista.
Jeff Wharton
MSysDev (C.Sturt), MDbDsgnMgt (C.Sturt), MCT, MCPD, MCITP, MCDBA
Blog:
Mr. Wharty's Ramblings
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