Partition Assistant: Unable to assign drive letter after trying splitting partitions

Hey guys I have a problem with Partition Assistant.

On a
laptop the C:\ (Disk) and D:\ (DVD+RW). The C:\ is 300GB with just 40 GB
of files. I wanted to splipt the partition C to 100GB and the other
partition to have the rest 200 GB.

1) I launched the partition
assistant and clicked the "split partition". I adjusted the size fo the
new partition and left the assigned letters as is (C:\ 100GB, E:\200)

2) It prompt me that it has to reboot to complete operation
3) It rebooted and started the procedure. Then after a while it stoped with the following message
"Unable to assign drive letter "

and nothing to fix it just to reboot.

When I rebooted, windows could not load and was stack in the following screen:


"Windows failed to start. A recent hardware or software change might be the cause. To fix the problem:

1. Insert your windows installation disc and restart.
2. Choose your language settings, and the click "Next."
3. Click "Repair your computer."

If you do not have this disc, contact your system administrator or computer manufacturer for assistance.

Status: 0xc000000f
Info: The boot selection failed because a required device is inaccessible."


So my questions are :

1) What did go wrong so that I can avoid this situation

2) How can I fix this

3) Are my files safe ?


  • The instructions were as I discribed spliting a partition in two parts. For having just a C:\ partition to have two partitions C:\ (100GB) and E:\ (200GB) [D: was reserved for the laptops DVD]

    It seems that the partition assistant messed up with the partition tables becouse when I booted the laptop from a live USB Linux the partitions were devided but the NTFS was messed up.

    Currently I am using a Windows Disk to run the startup repair and I will report back If I managed to fix it.

    P.S. This was a production machine and I have used AOMEI tons of times on other production machines and never had a problem. Partition assitant should have a way to at least produce a log file so that we can trace back the problems

  • Hi Murselat,

     Apparently this will happen sometimesimageYour files should be safe.

    Here is the link to P/A error codes and how to fix them

    P/A error code

    The 2nd one down sounds like what you came across.

    Error description:

    Failed to assign a drive letter for the volume, please manually add a drive letter for the volume by disk management.


    Failed to update drive letter, please manually set a drive letter for the volume by disk management.

    You will get this error code in case of below conditions:

    When assign the drive letter failed. -- Eg. The program attempts to change the drive letter from D to F but failed.

    When reassign the drive letter failed. -- Eg. The program reassigns the drive letter after finishing partitioning but failed.


    1. In case of assigning drive letter failed, you may reboot your computer and retry with Partition Assistant.

    2. Reboot your computer and you can assign the drive letter with Windows Disk Management.

    Let us know if this helps or another solution you have come across.

  • edited September 2014

    Unfortunatly Windows was not bootable so I was not able to run any tool.

    What I did was use the Windows Installation DVD to fix the partition table (using the startup repair). But even this did not fix the problem as the system was able to boot until login screen were it could not load the login screem.

    I had to use an Ubuntu Linux Live USB, and copy the files to external disk.

    Now I have to reinstall evrything as this is a work machine and it must be functional ASAP.

    Thing like this should not happen but, it is a lesson to always ha a plan B if somthing goes wrong

  • Sorry about having to re-install,

    couldn't you boot up with P/A and changed the letters from there?

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