Hi!

I wrote on this forum some time ago, sure to have solved my problem, but actually 
it hasn't been permanently.

I am experiencing the following issue: I have two DVD-ROM drives on my computer, 
named V: and W:, and two hard drives, C: and D:. The OS is Windows XP with (now) 
SP3, but the problem was occurring even with SP2. Sometimes, due to some weird reasons, 
after a reboot, DVD-ROM drives are changing their letters to E: and F:, the two smallest 
available letters. No matter if I change them back manually to V: and W: through 
Disk Management. This setting is kept for the duration of the current session. At 
the following reboot, they revert to E: and F:.

After checking about this issue on several forums, I understood that the last configuration 
I am trying to store in the registry, for some reasons, is marked as invalid and 
hence not kept, so Windows XP at the following reboot reloads the last known working 
configuration. Well, the problem is identified, yet far from being solved. After 
two or three months, I found out what I had thought to be a permanent solution by 
modifying the registry in the following way, without resorting to Disk Management 
tool among the administrative tools in the Control Panel.

The situation in the undesired configuration is shown under the following registry 
key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices

I find:
\\DosDevices\C: pointing to the first hard drive
\\DosDevices\D: pointing to the second hard drive
\\DosDevices\E: pointing to the second DVD drive
\\DosDevices\F: pointing to the first DVD drive
These two last ones, instead of V: and W:.

My workaround is the following:
1. rename \\DosDevices\E: into \\DosDevices\W:
2. rename \\DosDevices\F: into \\DosDevices\V:
3. create a new key \\DosDevices\E: as REG_BINARY
4. copy the content of \\DosDevices\D: into the newly created \\DosDevices\E:

These two last passages prevent Windows from re-assigning DVD letters at the following 
reboot in a wrong way, but anyway during the bootstrap Windows finds that the second 
physical hard drive is pointed both by D: and E: and automatically deletes E: (the 
higher one). So, at the following reboot I manage to save the configuration that 
I wanted.

This solves temporarily my problem. I have verified that from time to time, the issue 
is getting back. And unfortunately
I verified that not always this explained procedure is successful. Sometimes, I have 
to go along these steps three or four times, before obtaining the right configuration 
properly "recorded".

No explanation about the cause of this malfunctioning. Is there someone helping me 
in solving more permanently
this problem? This is really annoying, in addition to representing a loss of time...

Thanks, cheers,
Pietro M. Picca

Tip: Run a free scan for common Windows errors ad

re: CD/DVD letters changing after reboot Friday, October 30, 2009 at 3:42 pm Posted by Steve (23811 messages posted) Install Tweakui, and use it to change the Drive letters. Maybe they will hold then [Reply or follow-up to this message] re: CD/DVD letters changing after reboot Saturday, October 31, 2009 at 2:32 am Posted by Petercraft (1 messages posted) Thanks for your reply. I have already tried to use Tweakui and it behaves like Disk Management: at the following reboot letters are changed. The only workaround which I found is modifying myself letters in the registry, but anyway this works only sometimes. There is a number of cases when the problem occurs anyway: I cannot understand what particular I have done in the previous session. I even thought that I'm dealing with a hardware failure: Windows behaves like it doesn't know the drive yet and reassign a letter, but in this case I guess I should experience other issues during normal running, and I don't, so probably I am not on the right way... Thanks again On Friday, October 30, 2009 at 3:42 pm, Steve wrote: >Install Tweakui, and use it to change the Drive letters. Maybe they will hold then [Reply or follow-up to this message] re: CD/DVD letters changing after reboot Saturday, October 31, 2009 at 4:16 am Posted by MartinM (7551 messages posted) Have you tried deleting the drives and letting Windows re-discover them ? Worked for me in a similar situation but I know its not always effective (that is to say we are clutching at straws here !). It seems - as you have observed and so have I - that drives can get into some sort of twilight zone where they are known by XP to exist but are not fully integrated so they get whatever letter is next available when they appear in the boot sequence. [Reply or follow-up to this message] re: CD/DVD letters changing after reboot Saturday, October 31, 2009 at 7:36 am Posted by Steve (23811 messages posted) The next thing to try is uninstall the Optical Drives in Device Manager, and restart the Computer. [Reply or follow-up to this message] re: CD/DVD letters changing after reboot Saturday, October 31, 2009 at 8:18 am Posted by Adam Bradley (8787 messages posted) Try disconnecting it from the motherboard for a few boots to let windows clear its digital head of the drive. Maybe then windows will pick it up right? Best shot in the dark I can think of. On Saturday, October 31, 2009 at 2:32 am, Petercraft wrote: >Thanks for your reply. I have already tried to use Tweakui and it behaves like Disk >Management: at the following reboot letters are changed. > >The only workaround which I found is modifying myself letters in the registry, but >anyway this works only sometimes. There is a number of cases when the problem occurs >anyway: I cannot understand what particular I have done in the previous session. >I even thought that I'm dealing with a hardware failure: Windows behaves like it >doesn't know the drive yet and reassign a letter, but in this case I guess I should >experience other issues during normal running, and I don't, so probably I am not >on the right way... > >Thanks again > > [Reply or follow-up to this message] Tip: Use one of the [Reply or follow-up to this message] links above to add a message to this thread Search this forum Start a new thread on a different subject Report abuse of the forum Return to the Windows XP Discussion Forum