Problem with Windows Movie Maker.

[The Liar XIII]

The past little while, I've been having some problems with my Windows Movie Maker. It seems that I cannot save my movies because I keep getting an error message which reads Windows Movie Maker cannot save the movie to the specified location. Verify that the original source files used in your movie are still available, that the saving location is still available, and that there is enough free disk space available, and then try again.
I got everything in a specific place where it is easy to find. *cough* my documents *cough*, so it is easy to find, but what's on my mind is that I'm using some videos I've extracted from Youtube using Keepvid. Would that affect anything?
I was reading up some stuff that said that the location where I save the video should have a nice bit of room, well, there are only like 3 videos there, though, I only got about 14GB oh hard drive space left.
I was watching a video on Youtube (Which you can find [color="Red"]here[/color]), and I did exactly what he said to do, and still. I get the same error. Though, as he stated in the description, since this video was uploaded, Microsoft uploaded Service Pack 3. Would that affect anything?

I hope I don't have to reformat my computer.. AGAIN.. Err! I got everything I lost the first time, and now I might have to lose it again!

Anyone know what's going on?

Your help will greatly appreciated.