Have a look at the Disk Management console in Computer Management (Start > Run type compmgmt.msc, click OK).
How does the drive show up there? Any "unallocated" space on the drive?
I didn't find anything there :S
It seems that the free memory space is going DOWN even I am not doing ANYTHING... What the heck :conf:
Right now it shows 175gb, even few hours ago it was still at 192gb. I have not done anything during that time.