Q: i can't download itunes on my pc, it keeps saying apple support is required to run itunes , what do i have to do

ive been using itunes for yrs, all my music was stored on it, i got up the other day and couldn't open my itunes, i'm running a 64-bit on my computer, i deleted itunes just to see if i can reinstall like it was telling me, now i can even install it on my computer, it keeps saying that i need apple application support to run itunes, please unistall and install again, error 2(windows error 2), what can i do, i'm so upset because i purchased alot of music from itunes