Hi I have just upgraded my new laptop from vista to windows 7 via a disc from Acer. As it was new i didn't have much worth saving so I opted for what I thought was a clean install. All went ok, but now I notice my hard disc is showing 109gb disc space used when before it was only 20gb ish. Obviously I have done something wrong, the question is what and how can I rectify it. Any help would be most appreciated.