|281MB is a good start, but don't ask us if it's enough or not -- are you still having the issue?|
I would steer away from using Compression to save disk space. Microsoft says it won't affect performance, but i've experienced issues with this in the past - especially because you actually need as much free space as a file would require, UNcompressed, in order to move it on or off the drive.
your Hard Disk Drive (HDD) looks like about 250GB total? If it is full of programs and applications, i would suggest making sure you still need all those apps installed, otherwise consider uninstalling them. If you have a lot of photots/movies/music on the drive, i would suggest you consider aquiring another internal HDD, or an external drive, to store your media. Movies and Music in particular can take up a lot of space, and do not need to live on the system partition (C:\).
If you've already run Disk Cleanup, here's another good place to check for files you can delete: in a Windows Explorer window (My Computer, My Documents, any window) go to Tools, Folder Options, click the View tab, and switch to "Show hidden files and folders." Then go to C:\Windows, and you should see a bunch of hidden folders, probably with blue names instead of black, named something like "$NtUninstallKB9778338$." These are temp files from Windows Updates. IF you KNOW that you will NOT need to UNINSTALL any windows updates, these folders can be safely deleted, but keep in mind that after deleting, you will not be able to uninstall any Windows Updates.
Another good program for deleting junk files is "CCleaner." Helps identify junk files and junk registry keys.
"WinDirStatPortable" is also useful in determining which folders in your C:\ partition are taking up the most space.