Windows 10 Upgrade Added a Partition

After the upgrade to Win 10, I've got a new partition/volume on my SSD of 471 MB...

In Win 8.1, that read as follows...

Partition ### Type         Size         Offset

---------  --- -------        --------   ----------

Partition  1    System     500 MB   1024 KB

Partition  2    Unknown   40 MB     501 MB

Partition  3    Reserved  128 MB     541 MB

Partition  4    Recovery  750 MB     669 MB

Partition  5    Primary    921 GB    1419 MB

Partition  6    Recovery      8 GB      923 GB

Volume  ### Ltr Label                Fs      Type         Size      Status       Info

---------  ---  --- --------           -----    ---------- --------  ---------    --------

Volume   0    D   DVD-ROM                                      0  B   No Media

Volume   1    C   PCR Hard        NTFS   Partition   921 GB  Healthy    Boot

Volume   2         ESP                  FAT32 Partition   500 MB Healthy     System

Volume   3         WINRETOOLS NTFS   Partition   750 MB Healthy     Hidden

Volume   4         PBR Image      NTFS   Partition       8 GB  Healthy     Hidden


(1) What is it?

(2) How can it have been added w/o changing the Win 8.1 sizes & offsets?

Here's what it looks like now in Disk Management...


Thank you for posting your query in Microsoft Community.

The issue might arise if the space provided for the recovery partition has been occupied and a new partition has been created to place the leftover recovery files. In Windows 10, some additional space is allocated for the recovery files if the designated partition is filled to the brim.

In this case, I would suggest you to unhide the partition and check what type of files are consisted by the partition. In order to unhide partition:

  1. Start Disk Management (diskmgmt.msc) on your computer and take a closer look at your hard disk. Note the disk number and the partitions.
  2. Start DiskPart and select your disk: DISKPART> select disk 0
  3. List all partitions: DISKPART> list partition
  4. Now, select the hidden partition (see step 1) DISKPART> select partition 1
  5. Type DISKPART> detail partition and verify that it is hidden. Remember the Type value, this will be handy if something goes wrong.
  6. Set the type of the hidden partition to 07. Type DISKPART> set id = 07 override
  7. If everything goes ok, you will receive the following message “Diskpart successfully set the partition ID.
  8. All done. Type Exit to close DiskPart.
  9. Check the Disk Management to see witch drive letter has been assigned to the recovery partition.

Hope this information is helpful. Do let us know if you need any further assistance, we will be glad to assist you.

Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Thank you, Singh. Here is the partition detail info. Again, this matches my Win 8.1 info precisely including the offsets, which are in bytes this time.

(1) How can it be the offsets & sizes remain the same with a new partition added?

     -- The partition seems not to have been added at the end of the disk.

     -- I dimly recall seeing I had only ~1 MB unallocated anyway (somehow in Seagate's DiscWizard).

     -- DiscWizard & MS's System Image Backup do happily still work & report no error.

(2) Which is the true physical location of the new 471 MB partition?

     (a) 6th place going by diskpart list partition.

     (b) 4th place going by diskpart list volume.

     (c) 6th place going by offset. (I guess this is it.)

     (d) 5th place going by DiscWizard's Disk Mode view (below) & Disk Management (above).

     (e) 4th place going by DiscWizard's Partition Mode view (below) & Disk Management (above).

(3) Why do neither Disk Management nor DiscWizard show DiskPart's 128 MB partition 3 (reserved)?

(4) I believe partition 7 (8 GB) is my Dell system image of Win 8.1.

     -- Is it best not to unhide that one?

(5) My 40 MB Partition 2 (called Diags by DiscWizard) was reported to be empty by DiscWizard

      when I viewed it in Win 8.1 - now it is full. Could that be what you meant?

EDIT 8/23/15:  OK. I see what happened. Partition C: was shortened & the new 471 MB partition put between it & the Dell image of Win 8.1. None of the numbers changed because offsets are partition start positions (unchanged), & the size of C: isn't reported precisely enough by DiskPart to reflect the loss.

DiscWizard's Disk Mode shows...

DiscWizard's Partition Mode shows...


Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.

Reply In reply to deleted message

Thank you, hjlhv. That's an informative site. Once, I hoped DiskPart &/or Disk Management would do all I needed. But, if I've got a useless partition preceding C: on my disk - or even useful ones that have much unused space inside - I'll need something like AOMEI to merge the space into C:. If Terabyte is still around, I think I owe them a look too, though. Terabyte was useful to me back in my Win98 days.

I was BINGing around to discover what was my new 471 MB partition. AOMEI has convinced me it is Win 10's version of WINRETOOLS (as named in DiskPart list volume). Of course, the new one has no name. Win 8.1's version retained the name, & I guess it's still there in case I want to revert. (In my BINGing, I discovered people who did revert from Win 8.1 & then repeated the upgrade - got an additional unnamed WINRETOOLS each time. The old ones were never deleted or reused. Looks like that would happen again with Win 10.)

I believe space for my 471 MB unnamed WINRETOOLS was taken from the end of C:, & the 471 MB partition was situated between the shortened C: & my Dell factory system image (PBR Image of 8 GB). Finally, I've realized DiskPart list partition shows the actual order of my partitions on the SSD. I didn't at first see those offsets are in order lowest to highest. Seeing the offsets in bytes using DiskPart detail disk (as Singh instructed - but I had a set of them from Win 8.1) this time finally sunk it in. DiskPart list volume puts names on some, which can be matched to the partitions by sizes. I also see names in Seagate's DiscWizard, which can be matched by position...

So, what are these partitions?

Partition 1:  500 MB. Label is ESP. Status is EFI System Partition.

                    Need it be this big? What is it for?

Partition 2:  40 MB. Label is Diags says DiscWizard. Status is Primary Partition.

                    Is this from MS or from Dell, i.e., is it Dell's WINRETOOLS? Dell's BIOS diagnostics?

Partition 3:  >> 128 MB. Label not shown. Status not shown.       <<

                    >> This shows up only in DiskPart. Type is Reserved <<

                    >>  What is this?                                                         <<

Partition 4:  750 MB. Label is WINRETOOLS. Status is Recovery Partition.

                    I do believe this belonged to Win 8.1 & is now not active. Needed it be this big?

                    Would it reactivate were I to revert to Win 8.1? Or does revert create a new one too?

                    I believe (from AOMEI) that my Dell has its own WINRETOOLS somewhere else.

                    Would Dell want this around - or recreate it - should I go back to factory image?

                    This is a big, big candidate for deletion.

Partition 5:  921 GB. Label is PCR Hard. Status is Boot, Page File, Crash Dump, Primary Partition.

                   I may relabel that to PCR Solid, when fully convinced I've got an SSD in here & not an HHD.

Partition 6:  471 MB. No label. Status is Recovery Partition.

                   Win 10's WINRETOOLS. Shift+Restart goes here & produces the Choose an Option screen.

Partition 7:  8 GB. Label is PBR Image. Status is Recovery Partition.

                   This is my Dell factory system image. Going by AOMEI it may also contain Dell's WINRETOOLS.

                    It has the same type as my two other WINRETOOLS, so maybe so.

                    But then what is Diags - hmm, that could be my Dell BIOS diagnostic tools.

                    This is another candidate for deletion. I believe it's on my Win 8.1 Recovery USB, anyhow.

Edit 9/4/15: The following command indeed shows Partition 6 is my active WIN 10 Recovery Partition, & that Partition 7 is the Dell Factory Image...

===== This is still a post in progress. Will be edited.  =======

===== But I think I've done enough now for a week. =======

===== Still, any further help is very welcome.            =======


Did this solve your problem?

Sorry this didn't help.

Great! Thanks for marking this as the answer.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this response?

Thanks for your feedback.


Question Info

Last updated September 15, 2020 Views 7,759 Applies to: