Recently I and a good portion of my friends have been realizing that our disk space from files we have deleted in the past is not reallocated as free space. (And by delete, I mean delete, not that pansy Recycle Bin) This has happened to people with both FAT32 and NTFS partitions. The only way to regain your space is to use Norton File Unerase (which costs money) and try to recover the files. You then will need to either slip into a decent OS and delete the files, or log out of XP and log in on a different account and pray XP actually deletes the files.
Personally, I'd stick with 2kpro. Remote Desktop is about the only useful feature, but there are many third party products that accomplish the same task.