monline

There's a "Devices: Restrict CD-ROM access to locally logged-on user only" setting in the Local Security Policy of Windows XP Professional. One could think that "locally logged-on user" means a user logged on at the console. However Microsoft thinks different: a locally logged-on user (at least regarding this one policy) means the user who logged-on first, regardless of whether it was at the console or through Remote Desktop.

So if you've got "Fast User Switching" enabled, log in with a user, then log in with another user, the second login will be considered "not local". This means that if you enable the above mentioned security policy and log in with two users (one after the other), then the second user will not have access to the CD-ROM (or DVD-ROM ... or whatever). This access restriction can have several effects. Once I experienced that double-clicking on the icon of the DVD drive replied that there was no disc in the drive. At another occasion it let me enter the drive-view, but it did not display the contents of the disc. Apparently MS has implemented some random algorithm for the effects of this restriction. :-> Funny, isn't it? However I prefer predictability in respect of computer systems.

PS: the above described phenomenon was experienced with SP2 and all (at the time) available updates installed.