I have just tried to use a CD in Windows 7, but it doesn't seem to be recognized. I have just used the same CD in the same drive on the same machine when I was booted into Linux, so hardware seems to work fine. I am also sure I used it in windows a couple weeks ago.... Any idea how to find out what is wrong and fix it? I have an old type IDE/ATA DVD burner.
The best place to start is the device manager just to see if Windows sees it at all. From there you can see if there are errors that windows sees with it or its drivers - its possible there has been some corruption since the last time you used it. If windows doesn't see it, its possible that something else is going wrong (such as windows having issues with the IDE controller, which you'll also see in device manager if that is the case).