Watch this video to learn how to use Windows' built in cleanup software to reclaim memory space by removing old backups of windows. 1. Go to the start search bar and type in "disc cleanup". 2. Click on disk cleanup and wait for the program to gather information about your computer. 3. When it is done, go to "more options". 4. Click "clean up" on "system restore and shadow copies" option. 5. Click delete. 6. Close the window. Depending on how old your computer is, you should have reclaimed quite a lot of space.