Installing x64 Beta has lost access to my C drive

Hi, I've got a bit of a problem with the x64 Beta of Windows 7 which has got me stumped. When I tried previous builds (including the x86 version of the Beta) it installed fine on my second hard drive in my laptop (Drive E - I have partitions C: and D: on my main hard drive, which runs Windows Vista x86)

But when I install the x64 version of the Beta on Drive E, after Windows 7 boots (which it does fine) then the drive that Windows 7 is on shows in "Computer" as C: - my D: partition also shows up (and is correct) but my Vista drive does not show at all. Does anyone know a way around this? When I install 7, I just select Drive E to install on as normal, so not really doing anything differnt, except, of course, you can only install the x64 version by booting off of the DVD - whereas when I install the x86 version, I always start setup from within Windows.

If I could resolve this it would be great - I have no problem with installing 7 again if needs be. I should also mention that Vista still boots fine from C.
Thanks for any help

I have exactly the same situation, i am working on solving it and will post once i do

Solved.
open computer managment
click on Disk managment

you will see the C drive but without drive letter.
Right click on it and choose (Change drive letter and paths) and choose a drive letter of your choice. Note that you can not change the drive letter anymore.
Thats it it will work

Cheers

Thanks for this.

Trouble is I can't have my Vista drive as drive C again - I was just wondering why it now decides to use Windows 7 as the C drive rather than the E drive?

I will not do it my self but maybe you find this article useful:

1. Make a full system backup of the computer and system state.
2. Log on as an Administrator.
3. Start Regedt32.exe.
4. Go to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
5. Click MountedDevices.
6. On the Security menu, click Permissions.
7. Verify that Administrators have full control. Change this back when you are finished with these steps.
8. Quit Regedt32.exe, and then start Regedit.exe.
9. Locate the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
10. Find the drive letter you want to change to (new). Look for "\DosDevices\C:".
11. Right-click \DosDevices\C:, and then click Rename.
    
    Note You must use Regedit instead of Regedt32 to rename this registry key.
12. Rename it to an unused drive letter "\DosDevices\Z:".
    
    This frees up drive letter C.
13. Find the drive letter you want changed. Look for "\DosDevices\D:".
14. Right-click \DosDevices\D:, and then click Rename.
15. Rename it to the appropriate (new) drive letter "\DosDevices\C:".
16. Click the value for \DosDevices\Z:, click Rename, and then name it back to "\DosDevices\D:".
17. Quit Regedit, and then start Regedt32.
18. Change the permissions back to the previous setting for Administrators (this should probably be Read Only).
19. Restart the computer.

Hope it will work fine with you

Warning from the articale writer:

Do not use the procedure that is described in this article to change a drive on a computer where the drive letter has not changed. If you do so, you may not be able to start your operating system. Follow the procedure that is described in this article only to recover from a drive letter change, not to change an existing computer drive to something else. Back up your registry keys before you make this change

Thank you m22472 (interesting name ), I have been searching for this solution all afternoon!

Just signed up to say it works, and click the "thanks" button for you.