The disk defrag in windows 7 is very slow (as it has been in every version of windows) and starting in vista microsoft also removed the drive analysis info (thinking no one would miss it). So I suggest you download \"Defraggler\" from
Defraggler - Defragment your files! it has the ability to only defrag fragmented files (fast) or the whole drive. it also displays the drive analysis. It's fully compatible with Windows 7.