Both my DVD-Burners have stopped recognising any media

It seems like Alcohol screwed up something in your system.
Try one of the following:

1) Go to hardware devices tab and remove both DVDs from the list, then click on Scan for New Hardware. That should make windows re-detect your drives and install the proper drivers back. Then reboot and all should be fine.

2) Re-install Alcohol and the uninstall it again. If something went wrong the first time, it might not go the second. I have done this before and worked in a similar case like yours. Re-installing Alcohol fixed the problem, and after the 2ond uninstall all was good that time.

3) Reinstall your chipsets drivers (VIA, Intel, whatever...). That will reload the drivers for your DVDs and HDs and after a reboot all should be working fine.

Good luck

re-install your ide controllers... just open device manager and rightclick unintall and uninstall them, then restart and will auto be re installed, try it  

See here for info from Microsoft about this problem.

Ok I took the microsoft solution of deleting the registry entries and that worked .... but only for one dvd drive.
(There was no upperfilter registry value to delete, only a lower filter).

How do I do it for the other drive?

Bump - how do i fix the E:/ (the solution only fixed my D:/)

You should have followed our advice and not play with the registry! It is not recommended for novice users for obvious reasons. Our way was much simpler.

No need to get tetchy. I tried all three simple ways you suggested before making this thread and none of them worked. Thus the registry deletes were the next best suggestion.

The problem is back to its original state - neither are acting as burners any more (though for a brief period they did work after deleting the registry entries - though those entries have not returned). Occasionally one of them (D:/) come back as a dvd-rom, but not always.

No need to get tetchy. I tried all three simple ways you suggested before making this thread and none of them worked. Thus the registry deletes were the next best suggestion.

The problem is back to its original state - neither are acting as burners any more (though for a brief period they did work after deleting the registry entries - though those entries have not returned). Occasionally one of them (D:/) come back as a dvd-rom, but not always.

From what you wrote above: "I took the registry solution..." you imply that you didn't try the other ones first. Anyway, a repair install of your Windows could do the trick, and if that doesn't work, then a clean installation should do it.

How do I do a repair installation? I don't lose anything do I?

I'm trying to avoid the reformat option if possible.

I'm running Astra32 (diagnostic program).

It shows both drives have the capabilities to write dvd's but both dvd's "class" is cd rom drive. I seem to remember the registry also calling the dvd drives cd roms. How do I change this?

For the repair:
I assume you are running WinXP? Just boot from WinXP CD, when it asks you the first time to perform repair, say NO,then another screen (i think you need to press F8, then second time asking you to perform repair, then click YES, point it to the drive of your installation and let it perform the repair. What it does, is overwrite all windows files, like in the first installation, but leaving intact all programs and documents or whatever personal settings. Of course there is always the case where something could go wrong and fuck up everything, so before you do anything always BACKUP!

Cheers - reinstalling windows did the trick

Sorry you had to go through all this ordeal, at least you learned a few new things about your system.  
You gain some experience, hehe
Glad it is working now.