There are so many programs and files on Vista, I know I don't need them all
but I don't know which are necessary and which aren't. Like all those video
and picture programs Help there has got to be a way to tell ?
In addition to the other good advice you're received, be aware that
there is *no* downside to having programs and files on your drive that
you don't need, other than they take up a little disk space. Unless
you are very short of disk space, there is no reason to worry about
things like this.
Moreover, if you are very short of disk space, the amount you can save
by getting rid of a few Vista files or programs you don't need will
not be big enough to make a substantial difference. The only real
solution to that problem is to buy a bigger (or a second) disk drive.
So my recommendation is to leave it all alone. There's no benefit to
getting rid of what you may not need, and a substantial risk of
deleting the wrong thing and getting yourself into trouble.