Hi, thanks for replying. I run AVG anti-viris, Zone Alarm, Ad-Aware, Ewido, Spyware Blaster, Spyware Detector, Spybot and have just run (& then uninstalled) another one whose name I cannot now remember., but with that lot, you would think I should be safe. I can boot from CD at startup,
I have discovered the following link : http://support.microsoft.com/kb/270008
which seems to describe my problem exactly, but although I found an Upperfilter relating to CD Roms (Not where MS said it would be) I cannot find a lowerfilter.
I Googled Code 31 and found a lot of relevant posts, but the link that everyone found to be a cure is now dead (Anyway, I run W2K, not XP).
I think that I need to work around this MS report, and am presently uninstalling everything I can find relating to CDs or DVDs.
If that doesn't clear things, I will move on to your suggestions!