Clean install on a OEM formatted GPT disk?


  1. Posts : 4
    Windows 10.0 (Build 10240)
       #1

    Clean install on a OEM formatted GPT disk?


    I'm thinking of a clean reinstall of Windows 10 because of some stability issues (Mail and Calendar apps not working, Store app can't update etc yada yada; also I would like to get rid of the OEM softwares that have persisted till now). I got my current version of Windows 10 from the free upgrade program, Windows 8 to Windows 10 Home.

    Now, this is what my disk looks like:


    Pretty sure that it's currently a GPT formatted disk and a UEFI enabled installation of Windows. I only ever tinkered with the partitions once for parting a huge C: to the 3 System, Productivity and Entertainment partitions.

    Now, my question is: Is it possible to clean install Windows 10 with UEFI on only the System (C) partition (i.e leaving the other partitions, including but not limited to Productivity (D) and Entertainment (E) intact) without cleanly wiping the whole disk?
      My Computer


  2. Posts : 2,790
    Linux Mint 20.1 Win10Prox64
       #2

    From Boot menu, select UEFI-USB/DVD installation from your installation media. On the first screen, hold down SHIFT + F10. You'll get an Admin Command Prompt:
    1. Diskpart
    2. select disk 0
    3. list partition
    4. select partition 1
    5. delete partition override
    6. repeat steps 4 & 5 for partition 2, 3, 4, 5 NOTE: there's a hidden MSR partition that you don't see from disk management.
    7. exit
    8. exit
    9. Continue to install Windows, select Custom then select the first unallocated partition
    10. Click next to let Windows create all needed partitions
    11. After Installation is finished, you should have: 450MB Reserved, 100MB System, 16MB MSR and your C drive + the last 2 partitions(25GB, 14.81GB)
      My Computer


  3. Posts : 4
    Windows 10.0 (Build 10240)
    Thread Starter
       #3

    Thanks for your reply, topgundcp!

    Here is a screenshot of the partitions, better detailed:


    Your instruction involves deleting a few partitions numbered 2, 3, 4 and 5. My concern over deleting the #3 1GB OEM partition is that doing so will most likely render Lenovo OneKey Recovery - the reset-to-factory program - unusable. As I understand it, when invoked from boot menu, OneKey Recovery is ran from #3 partition; the restore image itself is stored in #9.



    I would like to retain the ability to reset my laptop to factory default if possible. Is there no way to install Windows 10 w/ UEFI on only the #5 (C: System) partition, leaving those data and recovery partitions untouched?
      My Computer


  4. Posts : 2,790
    Linux Mint 20.1 Win10Prox64
       #4

    If you want to keep those partitions then I would suggest to create a backup image to an external HD using Macrium Reflect Free which includes Partition 1 thru 5 then do the steps above so you can restore back to the way it is now.
      My Computer


  5. Posts : 4
    Windows 10.0 (Build 10240)
    Thread Starter
       #5

    That's a great suggestion! I think it will be enough to back up only partitions 1-4 because the #5 system partition is not crucial to the OneKey recovery software. There might be a small hassle with the partitions not get to keep their original types: Recover Lenovo One Key Rescue after Resizing Partitions but I believe I can figure that out. For now I will just go ahead and create a rescue USB for some peace of mind.

    Once again thank you for your replies!
      My Computer


  6. Posts : 2,790
    Linux Mint 20.1 Win10Prox64
       #6

    When using Macrium to back up those partitions, they will be restored back to the original partition types so you should not have any problem. However, you should keep those partitions in current order when restore ie. the last 2 partitions should be #8 and #9 so onekey recovery can find them.
      My Computer


  7. Posts : 11,203
    Windows / Linux : Arch Linux
       #7

    Hi there

    Note - when using DISKPART the LIST DISK command will show an '*' for GPT formatted disks if you are unsure of which of yours are GPT formatted.

    Clean install on a OEM formatted GPT disk?-diskpart.png

    Cheers
    jimbo
      My Computer


  8. Posts : 2,790
    Linux Mint 20.1 Win10Prox64
       #8

    @jimbo45
    In addition, There are couple of ways to find out whether it's MBR or GPT:
    1. From disk management. Looking at 2nd partition then you can tell it is GPT
    2. Or move the mouse pointer to Disk 0, right click->Properties->Volume. It should tell you it is GPT.


    Clean install on a OEM formatted GPT disk?-.jpg
      My Computer


  9. Posts : 11,203
    Windows / Linux : Arch Linux
       #9

    topgundcp said:
    @jimbo45
    In addition, There are couple of ways to find out whether it's MBR or GPT:
    1. From disk management. Looking at 2nd partition then you can tell it is GPT
    2. Or move the mouse pointer to Disk 0, right click->Properties->Volume. It should tell you it is GPT.


    Clean install on a OEM formatted GPT disk?-.jpg
    Hi there

    Thanks for the info -- I just added mine in case the OP was in the middle of doing something and it's often easier to open cmd prompt in a small windows and quickly see.

    Perhaps I'm too used to Linux so I don't mind using the cmd line / prompt --using the cmd prompt seems to be a dying art these days !!!!!

    cheers
    jimbo
      My Computer


  10. Posts : 4
    Windows 10.0 (Build 10240)
    Thread Starter
       #10

    Windows X - A was one of the first shortcut combos I learned upgrading to Windows 10. I don't mind command line interfaces at all, earlier I used EaseUS PM because it allowed viewing the hierarchy of the hidden partitions as well and showing detail info about them. Thank you both for the new alternatives. :)
      My Computer


 

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