Ccleaner is free. The donation is optional. Scroll down past the donation and click the link to download from piriform or filehippo
Mod 80 – you might be right that they don’t know what the problem is. But those are generally good advice for getting things to work.
When you say “there is enough memory” are you referring to RAM or Hard Drive space. Some people confuse those two. If it is crashing in the middle it might be a RAM problem. Have you tried restarting the computer and closing all programs besides the movie maker?