When I attempt to open a blank CD in an Explorer window it tells me ":\ D is not accessible; incorrect function". However, I can burn CDs with programs like iTunes or Nero. Any thoughts on why the simple open-the-blank-CD method doesn't work anymore?

I don't know why you'd want to open a blank CD, since anyway there's nothing on it. Do you actually mean adding data to it from explorer?

As for why its not working, its because you have disabled CD-writing functionality. To get it back, the below steps:

1. Start>>Run "services.msc"

2. In the list, look for "IMAPI CD-Burning COM Service" and double-click it.

3. Now change the "Startup type" from dropdown box - it was "disabled", now make it "Automatic".

4. Click "Apply" button to apply the change.

5. Reboot.

That's it, it should now work fine.

Yeah, that's what I mean, open it for adding data. Hmmm... it went back to working. I don't know what was up with it for a while there... hopefully it just keeps functioning

It's doing it again... I made sure the IMAPI CD-Burning COM Service was enabled and started, it's still giving me trouble...

Under the properties for the drive, then under the recording tab, is the "Enable Recording On this drive" enabled? If it is, and it isnt working if the service is listed as automatic, then try un-installing roxio or nero if you have those installed. In my experiance Nero (possibly roxio) screw that windows function up when they are installed.