Note: The following unrelated newsgroup was omitted in my reply:
microsoft.public.windowsxp.hardware
Not a hardware issue but instead a Windows configuration issue.

wrote:

I have two external hard drives. Whenever I turn one on, I get a
couple of unwanted windows asking me what to do. Ergo I want to
disable autoplay in this case, in order to speed things up. I have
tried gpedit.msc to get a Group Policy window from which I selected
Administrative Templates \ System. I turned off Autoplay.

I see that I had only two choices - turn off autoplay for ALL DRIVES
or for just CD drives. I wanted just the reverse, leaving autoplay ON
when I play a CD in the CD drive.

Get the TweakUI powertoy for Windows XP. It's gives you the following
choices regarding AutoPlay:

- Enable autoplay for CD and DVD drives
- Enable autoplay for removable drives

In your case, you want to select the first option but deselect the
second option. Is there a reason why you want to allow malware to
auto-run on an infected optical disc when you insert it into the drive?

http://support.microsoft.com/kb/967715 shows you the bitmask used to
determine which drive *types* have auto-run/play disabled or not.
Policies are just registry settings.