Does anyone know of a good program that is similar to garage band that works on Windows XP? Thanks!

The program named "Acid" is one of the closest programs to Garageband.
It's a Sony product and there is a basic version and a pro version as well.
Just like Garageband, the basic version is made almost specifically for putting together looped audio to compose music.

Fruity Loops is also a really good program that a lot of beginner up to advanced composers use.

Acid is decent. Fruity Loops is great.

I use Fruity Loops for a lot of stuff, it's a hell of a program. You hook up a midi-keyboard and you're in business.