DiskSpaceGuard

From Soft-On-Line:

The program DiskSpaceGuard reserves free space on hard drives of your computer. Some people try to solve the problem installing a huge amount of the different unuseful programs and games and then they remove them one by one. As for us, we think this way of reserving free disk space is uncomfortable and not very effective. Our DiskSpaceGuard is designed to reserve free space on hard drives of your computer.

The powerful and easy-to-use management features in DiskSpaceGuard help you take control of your disk space easily. When you need you can always free as much as you need disk space on your hard drives easily by a single click on a slider. The Administrator Diskette (which will be created durning installation) will hide from other users the fact of disk space protection utility presence. So even MS Windows will not see the hidden disk space, considering it to be used.