Weird problem CD Drives

New to this, good so far

Windows XP home, 3 yr old Microstar PC.
Both CDROM drives have stopped working, BIOS sees them, XP sees them, no "!" anywhere or any evidence that XP knows there's a problem. Disk spins, Windows sees it (autostart icon), tries to access and then stops, same on both drives .. boo. Also the (ipod) USB memory stick is detected by XP, designated a drive letter okay, but then disappears again as if it was never plugged in, but it's light stays on. Thought maybe drive designation problem, "C" is master, then there's a "D" Backup, "E" Restore, plus "F" & "G" for the opticals. Stick is "H" for about 5 secs before it does one. Don't know where to go from here. Help appreciated.