It sounds suspiciously like nefarious DRM. But I have never heard of anything like that before. I can only speculate that there is some service somewhere that was secretly installed with some other software that, upon detecting an unsecured digital connection, disables your DVD-ROM. In other words... I blame them
. Who are them? Maybe Sony, Macrovision, the RIAA, ninjas, the IRS, Comcast, etc.
You can try using Serviwin
(it's great!) to disable services and drivers from companies other than Microsoft. Try Autoruns
too (with the setting to verify signatures). Just go through and see what happens if you temporarily stop services and junk from companies you don't think have a reason to be on your computer, as long as you are sure they are not necessary. You may want to back up your registry first. And if you do something bad in Serviwin, like disable your USB drivers (which I did), you can put the HDD into another computer that works correctly and change the settings back from the other OS. In other words, it is basically safe even if you disable utterly vital drivers... but it is better to just "stop" them instead, so that if you mess up, when you reboot everything will be back to normal.