First let's clarify the terminology. "Memory" refers to ram and swapfile. You are talking about hard disc space.
When you deleted the files they went to the recycle bin. Empty the Recycle Bin. Run Disc Cleanup. When you do, click on the "more options" tab and choose to clean up restore points. This will delete all but the most recent restore point - that should free up a LOT of space. Let us know.