How do I know whether my Windows is 32-bit or 64-bit ? Print this pagePrint this page

Please read following posts at Microsoft Knowledge Base which will help you determine this :
1. http://support.microsoft.com/kb/827218
2. http://windows.microsoft.com/en-IN/windows-vista/32-bit-and-64-bit-Windows-frequently-asked-questions

General thumb rule is, if you have Program Files  AND Program Files(86) both the folders in your C drive (or whichever drive in which you installed Windows), you are running 64-bit Edition of Windows. If you have only Program Files folder then you are having 32-bit Windows Edition.