Originally Posted by metaschima
Go to System information and check your processor make and model, it is probably also listed in the BIOS settings screen. Then post it here or check online to see if it supports 64-bit.
Thats IMO the easiest way, to get the CPU model from the BIOS then search for the full model number. Some CPUs are hard to figure out if they are 64bit or not from limited info you get from 'system information'.
There is another way you can get windows to tell you more about the CPU.
Start -> Run 'dxdiag'.
But it will only give you more info than 'system information' sometimes, other times you wont.