Thank you for your response.
I didn't mean read, I just meant recognize a blank disc. The two previous Sony DVD burners and the new Plextor recognize that there is a disc in the drive using Explorer. They all showed it blank, but they at least said there was a disc in the drive. The new 7240 won't do that using Explorer, it just says "M:\is not accessible. Incorrect function." Maybe that is the way the 7240 works as there is absolutely no other problem with the drive.
The 7240 does everything else right:
1. It burns both DVD-R's and DVD+R DL's OK so far
2. It reads and plays all DVD's that I either created or that I own
3. DVD Identifer identifys the drive and any disc in it
4. DVDInfoPro does the same
So, as you can see, it does everything you can expect in a DVD burner except that one thing that is totally unimportant.
I am just trying to be sure that I do not have a defective drive that might cause me problems in the future. I own a total of five IDE DVD burners, and I never remember any of them not recognizing a blank disc in the drive using Explorer, this is the 1st known one. They all autostarted, and then you could explore any blank disc. There is no reason to do this that I know of, it was just the way it is/was. If you say you (or anyone) that has a DVD burner and you/they say it doesn't autostart and you can't explore the disc also then I would say that must be normal if it does everything else correctly.