The easiest way I know to find out what your memory is in your computer, is to go to the Crucial memory selector page and let it scan your computer.
It will then tell you which memory is compatible with your board.
Also PC Wizard 2008 is more up to date for identifying computer components.
You can reinstall Windows, even if it is an OEM disk, as that just means it is tied to that computer and cannot be transfered to another one.