Windows does all the work. Now. If you only use one drive at a time, Windows may assign the same drive letter. That's why I give my external drives specific drive names for their function like "storage", "backups", etc.
I have Windows XP Pro, sp3.
When I got my first external hard drive (HD), I thought it would be a hassle to get windows to see it but it was very easy. I just plugged it in, via USB, and it put a drive letter in Windows Explorer (WE) and I could access it like any other drive. It was easy.
My question is: if I get another external HD, can I use it along with my current external HD? That is, can I use the new external HD without unplugging my present external HD.