I have Windows 7 myself, and actually it DOES have Movie maker, I've used it myself.
It's just been renamed to "Windows *live* movie maker". Then again, I got it a year after your post.
Honestly though, the only issues I've found with it are reverse- compatibility. It has none. At all.
Tehpivot
XP is still pretty good, it has support for everything, and is pretty cheap. Windows 7 is real shitty, I mean come on, $1200 a copy for something that barely works?