Windows Vista, 2003 Server, XP, 2000. No any special requirements to hardware.
functional limitations:
Nag screen that appears during work sessions. 15-day limit.
DiskBoost description
Speed up hard drive operations with a virtual RAM disk! DiskBoost maintains a blazing-fast virtual disk in your computer's RAM, allowing you to make your computer faster by storing frequently accessed files and data in the operative memory. Temporary files benefit from being placed onto a fast RAM disk. Sensitive information is securely encrypted against unauthorized access, while important data will be backed up into a file on the hard disk.