check your Windows xp & vista is 32-bit or 64bit
Following these steps
1. Go to Start > Run > or press window logo + R type in “msinfo32.exe” and enter.
2. In the resulting window on the right panel you can see “System type”
3. If there it says “x86-based PC” then your system is 32-bit or if it says “x64-based PC” then its a 64-bit PC.