Video will not play or export

This program is beyond me. I have all of the specifications that it said it required and the program is barely running. Every time I make a few changes the program stops playing the video. I edited and deleted some programs on my PC which helped a little but now the video will not export. Or this program takes an insane amount of time to export a 50sec video. Please help. This is for a college project and nothing I've read or done has helped.