|Recyclebin reserves 10% of disk space = 15gb|
System Restore reserves 10% = 15gb
Even though they are empty , the space is still reserved.
You can adjust the size of each. Rightclick Recyclebin and select properties. For System Restore, go to START> AllProgs> Accessories> System Tools> System Restore and click on settings link.
Did the service tech recover your old data and put it in a backup folder somewhere on the new drive?
That would explain where most of your space has gone.
Goin' Fishin' (Some day)