Zim 7.11 and 8.20 now support both the 32-bit and 64-bit version of Windows 7, Windows Vista, Windows Server 2003 and Windows Server 2008.
Note: The Zim 7.11 Integrated Server is currently not compatible with the 64-bit version of Windows Server 2008.
Contact ZIM support at support@zim.biz
Visit the ZIM Support Forums for further assistance.