At least, I think it was the dual boot linux install that caused the problem. The drive is no longer visible under Windows, and it did work just before I installed Ubuntu.

Because I had to replace the hard disc in my laptop, and reinstall everything, I reserved 20G for another OS, and installed Ubuntu in it.

Yesterday, when I wanted to write a CD of slides I had scanned for use at Oxonmoot, I discovered that the cd drive was not listed in Windows file mangler, nor inthe device manager. I have run out of bright ideas about how to fix it, except reinstall windoze and don't dual boot. That would be another 2 days wasted, AND I'd lose linux on this machine. I had been hoping (gradually) to migrate away from Windows, at least partly.

What I have found out/tried so far:

• The CDROM works fine under Linux, and wrote the needed disc OK
• The CDROM is listed as the second boot device, after a USB floppy drive I haven't got, but if I leave a bootable CD in it, grub loads linux unless I take other action. I am not sure if it is even possible to boot to a CD. I need to test that, but I doubt it.
• Searching for problems with Win XP losing ythe cd drive, I found mentiion of a registry key under current control set, with an upper filter value. I removed it as instructions suggested, and now Windows lists the linux partitions as unformatted drives, but still does not see the cdrom drive.
• I first tried restoring windows to an earlier configuration with the system restor functin. The earliest one available, when the cdrom was definitely working, did not restore the functionality.
• I also tried fitting a cdrom drive that works in another computer, but that made no difference. Hardware failure is pretty much ruled out.

Can anyone figure out what I can do to make it work again?