You can't run 64-bit software on a 32-bit operating system, but the reverse is generally possible.
"The tools which would teach men their own use would be beyond price." - Plato
AMD Phenom II X4 945 @ 3 GHz
Windows 7, 64-bit
6 GB RAM at 533 MHz
GeForce 315
AMD Phenom II X4 945 @ 3 GHz
Windows 7, 64-bit
6 GB RAM at 533 MHz
GeForce 315