My question is: Is your computer a prebuild, or is it a name brand, like ASUS or Dell.
If its not name brand you can buy a new Dual core, (or quad core
) and your good to go
If name brand then = New Mobo, CPU and copy of windows + re-install.
Bottom line if you can't just simply change out CPU.... your best bet is to build a new little rig. Also if you can squeeze it. a 7750 is going to work out better for you than a 6770