Visual Studio 2010 and Visual Studio 2008 support both x86 and x64 Architecture.
Visual Studio 2010 support below Operating Systems:
Windows XP (x86) with Service Pack 3 - all editions except Starter Edition
Windows Vista (x86 & x64) with Service Pack 2 - all editions except Starter Edition
Windows 7 (x86 and x64)
Windows Server 2003 (x86 & x64) with Service Pack 2 - all editions
Users have to install MSXML6 if it is not already present
Windows Server 2003 R2 (x86 and x64) - all editions
Windows Server 2008 (x86 and x64) with Service Pack 2 - all editions
Windows Server 2008 R2 (x64) - all editions
See: http://go.microsoft.com/fwlink/?LinkId=133421