Originally Posted by Colossous 
You'll need 64 bit for it to recognise the 4gb !! 
Wrong im afraid. This is covered almost weekly at the moment
See
http://forums.hexus.net/showpost.php...1&postcount=24
Its hardware dependant - PAE, OS setup and a few other things.
You can use 4gb fine on a 32bit OS, provided you know how to do it.
Granted the 64bit version is a lot better (and easier) at handling that much RAM though.