One thing I have noticed in Windows 7 and Windows Vista is the amount of space wasted in Windows native applications.
The control panel has lots of apps that have wasted space.
Here is a small list:
Windows Anytime Upgrade
Speach Recognition Options
Backup and Restore Center
Native apps should not have wasted space (White Space), if more space is needed then apps should expand automatically.
I have used Windows Vista as an example you can see from the attached image what i mean, this problem is evident in Windows 7