I let my friend install a CD-RW for me. I think it's on the same bus(?) as my existing CDROM. It has worked once after much coaxing and searching for new hardware but now it just doesn't seem to accept it. It is on hardware lists and the properties say its working but there's no sign of it in 'my computer' and I can't read from it or write to it. If I search the computer for new hardware the light stops flashing and I can open the tray but it still does nothing. I have uninstalled it and added it again but that also did nothing. Is there something I've missed? Any help is much appreciated.

Boot the system into Safe Mode and enter the Device Manager and remove all CD ROM drivers including the CDRW drives listed and then reboot the computer and let them reinstall.

If this does not resolve the issue, then the problem is likely an incorrect jumper setting on the CD ROM drive.