Change OS Drive Letter Solved

  1. Posts : 3
    Windows 10 Pro 64 Bit
       01 Dec 2016 #1

    Change OS Drive Letter

    I've got a two hard drive laptop set up and I'd like the OS to be on my faster 256GB OCZ RD400 SSD but with a letter other than C: I don't care what letter, just not C.

    My larger 1 TB drive, is what I'd like to label as C: without the operating system on it. I use DropBox with my colleagues and the CAD references look at the drive letter - so my xref files, data shortcuts, etc.c won't be found if my DropBox folder is on my D drive.

    I've tried using Minipartition Toool Wizard and EasyBCD to copy the OS from one drive to another hoping it wouldn't always default to C: but it does. My laptop is set up for UEFI and GPT disks which is new to me and was quite confusing at first. I've tried using DiskPart to no luck - won't let me change the C letter. I even edited a file DOSDevices in REGEDIT - computer wouldn't boot after that...

    I have not seen any way in Windows 10 to change the drive letter during set up, etc. It's always C. I even installed the OS on both drives and had a dual boot setup - but it always made the OS drive letter C and I don't want the OS on my 1 TB drive - it is noticeably slower.

    Any thoughts are appreciated. Thanks. In summary, I'd like the OS with letter D: on my 256GB RD400 SSD and DropBox on my 1 TB HD with the letter C:.
      My ComputerSystem Spec

  2.    01 Dec 2016 #2

    In modern times now it's almost impossible to change the Windows OS drive letter to anything other than C: drive, and the complications arising to do so would be many. I would suggest using folder junctions instead. Let's say your CAD program uses C:\CAD_Data.

    1. Move C:\CAD_Data to D:\CAD_Data. C:\CAD_Data should no longer exist.
    2. Open a Command Prompt (Admin), in the Command Prompt (Admin) window run:
    mklink /J C:\CAD_Data D:\CAD_Data
    3. C:\CAD_Data will reappear on C: drive but the actual storage location for the data appearing there will be D:\CAD_Data

    If your one drive is auto syncing, set it to auto sync with the D:\CAD_Data folder.
      My ComputerSystem Spec

  3. Posts : 3
    Windows 10 Pro 64 Bit
    Thread Starter
       01 Dec 2016 #3


    Just tried it with a symbolic link and used /d instead of /j and it seems to be working! I was able to open a file which had numerous x-rederenced files - which it looked for on C drive and found them! Very cool!!! Thanks so much for your help - below is what happened when I tried a /J junction....

    I got the Mklink set up and it looked good - files were obviously stored on D but showing up on C - similar to a shared folder appearance in Windows Explorer. But AutoCAD wasn't happy - it simply paused and wouldn't open any file that had a x-referenced file. I used rmdir to remove the link and bam, the CAD file proceeded to open. So I appreciate your help as you answered my question... But I think AutoCAD has something going on where it's confused by the mklink... I did a quick search about using AutoCAD with junctions and there ain't much on the internet that I saw... Guess I have a unique problem!

    Really appreciate your help! Thanks again... oh well...
      My ComputerSystem Spec

  4.    01 Dec 2016 #4

    Looks like this forum thread suggests that using MKLINK /D instead of MKLINK /J will work:
    Solved: AutoCAD 2017 - Stuck in loop saving files with X-Refs - Autodesk Community

    C:\WINDOWS\system32>mklink /?
    Creates a symbolic link.
    MKLINK [[/D] | [/H] | [/J]] Link Target
            /D      Creates a directory symbolic link.  Default is a file
                    symbolic link.
            /H      Creates a hard link instead of a symbolic link.
            /J      Creates a Directory Junction.
            Link    Specifies the new symbolic link name.
            Target  Specifies the path (relative or absolute) that the new link
                    refers to.
      My ComputerSystem Spec

  5. Posts : 3
    Windows 10 Pro 64 Bit
    Thread Starter
       01 Dec 2016 #5

    Thank you!!!!
      My ComputerSystem Spec


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