While the save game folders are large (they keep track of a lot of stuff), they are also very compressible. If you don't want to delete older saves, they can be zipped to under 8% of their original size (
7-Zip would do a bit better than XP's built-in utility).
If you are deleting older saves and not getting the space back, then they are not really being deleted (in Windows Explorer check the subfolders in the '
..\Beyond Divinity\savegames' folder), or there is a problem with the hard drive or how Windows is reporting the free drive space (run ScanDisk).
Try deleting the files in the dynamic folders;
'
..\Beyond Divinity\Acts\Act1\Dynamic', '
..\Beyond Divinity\Acts\Act2\Dynamic', etc.
These folders are used as a cache for the game. Files are created / copied there from the save game folder when you load, and written / copied to those folders when you save a game. The files will be re-created as required the next time you start Beyond Divinity. If there was a corrupt file in those folders, deleting the files should fix the problem.
In general, for hard drive cleanup there are
various programs you can use to track down unnecessary files and folders that may be taking up too much space.