BSOD = Unmountable_boot_volume

I don't know if MS sent a patch Tuesday or not, but this happened on the first reboot since then.
Win 7 Home - Cannot access the C: drive.
When I choose repair option and open a cmd window it shows the drive as X: I can change to D: (cddrive) but when I try to access C: it says "There is not enough space on the disk."
No other "repair my PC" options worked either.
The harddrive shows in the bios. I can start (and then cancel) a new install and it shows the drive.
Chkdsk runs clean, but not sure it is checking the C: drive when run from the X: promt even though I typed chkdsk C: /f

I have tried to run SFC, but to get to the CMD window I have to use the repair option and it sets up a flag I guess that won't let SFC run w/o reboot which just sends me in a loop.

I do not have a restore disk or sys image. (not my PC... my sons)
Any suggestions are welcome.


Seems to me that the major problem is not having enough space on your C: drive.

I would download and burn as .iso Knoppix which is a Linux live cd. Boot to the cd after burning. Use this to delete unnecessary files to clear lots of room, if possible.

Then try the repair option again.

Thanks, but I failed to mention:
Still get the BSOD in safe mode
There is 113Gig available on the drive.


Try swapping out the cable to the hard drive with a different one.

Then if no good still, run the chkdsk /r command to see if it repairs, which it actually very well might.

Last edited:
Well nothing worked. To make it worse all he had was an upgrade version, which requires the OS to be working to upgrade it.
The new full version copy installed with no problems.

NOTE to self... back it up!

1. If possible, attach the crash dumps found in C:\Windows\Minidump

2. Use recovery disk Windows 7 System Recovery Disc to:

- startup repair
- command prompt -> chkdsk /r /f
- command prompt -> sfc /scannow

3. Since we don't have much info about your hardware, run memtest too:

RAM - Test with Memtest86+ - Windows 7 Forums

Could not get to the dump log files, as could not access the C drive(s). It is in an extreme gaming Sager laptop with a RAID setup.

We ended up installing a fresh copy of Win 7 already and had no problems.

I did not know about the recovery disk you mentioned in your reply. I burned them already. Thanks so much for those. I am sure they will help in the future.


Glad you reinstalled and it's good now. You don't need those recovery disks if you have 7 install DVD, I thought you didn't have it:

I do not have a restore disk or sys image. (not my PC... my sons)
You can create the recovery disk in Control Panel -> Backup and Restore -> Create a system recovery disk.

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