At 17:07 11/23/07, Larry Scroggs wrote:
>System specs are:
>   Homebuilt system (September 2005)
>   Windows XP Pro SP2 with all updates
>   PLEXTOR DVDR   PX-716AL  (D)
>   PLEXTOR DVDR   PX-740A  (E)
>
>System was working fine up until a month ago.
>Now various CDs and DVD disks are not read in either CD/DVD
>drive...


I had similar symptoms last year with my Windows 2000 computers.
(Neither CD or DVD drive would read.) The clue was that I could
still boot from these drives, so they worked until Windows was
loaded and running.

There is a Microsoft article mentioning that WinXP, Win2k, and
Windows Vista share this problem. See this Microsoft Knowledge
Base article: <http://support.microsoft.com/kb/314060/EN-US/>.

The problem can occur after an update to or removal of third party
CDROM or DVDROM burning software. Also, at least one security patch
for Windows Media Player affects the way Windows reads CDs and this
patch can cause the same effects.

Here's a more detailed version of the Registry fix described in
the above Microsoft article. I don't see that you have anything
to loose by trying this. It worked for me and didn't cause any
side effects.

Open Regedit (use the Start, Run menu) and navigate to

HKLM\System\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFCl-087002BEl0318}

(Note that HKLM is short for HKey_LOCAL_MACHINE.)

In the left pane of the Regedit window, highlite this key by left
clicking (once) on {4D36E965-E325-11CE-BFCl-087002BEl0318}.

In the right pane of the regedit viewer you'll find two subkeys
called "UpperFilters" & "LowerFilters". Delete the values for
these subkeys. (For example, right click on Upperfilters and choose
Modify from the menu that appears. In the small data window that
appears, drag your cursor to highlite everything (all the numbers)
and hit the delete key. You should be left only with 0000. Do the
same thing for Lowerfilters.) Close Regedit and reboot the computer
so that the changes that you made to the registry take effect.

See if your CD/DVD drives work work again.

This problem is common enough that the latest version of Nero
burning software (version 7) installs a utility that runs every
time you boot. This "filter check" detects and corrects this upper
and lower filter problem.

Regards,
Bill

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