Windows 10: Disk partition disappeared after CHKDSK

I have 3 HDDs and have each formatted with 2 partitions: OS and data, 500 GB in each partition.


I wanted to increase the size of the data partition by 300 GB for one of the HDDs something I have done before with no trouble. I decreased the size of the OS partition which as expected left an unassigned 300 GB space then increased the size of the data partition by using that space. It gave me the following in Disk Management:


Disk 1: 100 MB Healthy EFI F: 200 GB Healthy G: 300 GB Healthy G: 500 GB Healthy


I thought that was odd to have 2 "G" drives, but in Explorer -> "This PC" it appeared as a single G: drive of 800 GB and worked just fine files were present and I could copy new files to it.


A day or so later, after booting, CHKDSK ran for many hours about 6, repairing thousands of lost fragments and setting thousands of indexes.


After all that, the G: partition disappeared entirely, and it now has the following in Disk Management:


Disk 1: 100 MB Healthy EFI F: 1000 GB Healthy


Of course, all the data files have disappeared and "This PC" says there are about 840 GB free of 1000 GB.


I ran a SMART analysis and it reports there is nothing wrong with the actual disk.


DISKPART gives the following for that disk:


DISKPART> select disk 1

Disk 1 is now the selected disk.


DISKPART> list partition


Partition ### Type Size Offset

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

Partition 1 System 100 MB 1024 KB

Partition 2 Reserved 128 MB 101 MB

Partition 3 Primary 931 GB 229 MB


Of course I'd like to get the partition back and restore the files, but I'm not sure the best way to go about this. Any help would be appreciated.

:)

 

W7 Hard drive partition issue

to get rid of that 100 meg windows partition that setup creates for you on a new install on a blank hdd:

- press shift+f10 when on the partition management screen in setup <-- this opens a command prompt
- diskpart <-- start the windows command line partition management tool
- list disk <--- list the installed hdds in this computer for the next step
- select disk 0 <- might have to replace 0 with the number of the correct disk
- clean <-- this will erase all data on the disk you selected one step up- dont use the wrong disk!
- create partition primary <- creates a primary partition taking up all space on the drive, adjust the command if necessary
- exit, exit to exit diskpart and the command prompt
- click refresh in partition manager and select your newly created partition and install to that

 

Disk management console view is not up-to-date

i dont know how to fix your disk management, but i can fix your partition problems...




open up Command Prompt with admin rights. (Right click, run as admin)


enter in
DISKPART
list disk

then find the Disk number for your Raid array... lets call it number 7 ( you can tell what disk is what by the total size)
type in

Select Disk 7
List Partition (will give you a list of all the partitions..)
Select Partition 1 (im assuming you only have 1 partition on Disk 7) repeat this step if you have more partitions.
ASSIGN


that should get the array up and running ready to use.


EDITED.

any problems, post back ^^


Still EDITING *Stick Out Tongue

side question, have you tried restarting the PC?

 

Unable to recover missing partition: Error “You need to format the disk in Drive D”

Hi Perfmaster,

Thank you for writing to Microsoft Community Forums.

I can understand the inconvenience you are experiencing with the missing partition after installing the Update.

1. Do you see a partition showing up as a RAW in disk management?

The possible cause for the Partition loss or Deletion on Windows 10:

1. Sudden power loss can corrupt Windows 10 partitions, as a result, you will not be able to access the data present on it
2. Sometimes on Windows 10 operating system, converting the dynamic partition to basic type also damage partition table on hard disk drive result in partition loss that leads to huge data disaster
3. Mistakenly formatting the HDD partition to extend the size of the partition, repartitioning, or unintentionally selecting faulty drive of Windows 10 for formatting thereby you may end up losing all data stored in it and also wipes out your existing
   partition
4. If you attempt to a dual-boot or multi-boot environment to install and run multiple OS on the same system, then it might damage the existing file system and all the partitions will go missing from Windows 10 PC

However, you may try the below suggested steps to fix the issue.

Run check disk utility

Note: While performing chkdsk on the hard drive, if any bad sectors are found on the hard drive then chkdsk tries to repair that sector, if any data available on that might be lost.

When we encounter this kind of situation, first thing we have to verify if OS is able to detect the file system on the partition on it or not. Best tool to verify this is to run chkdsk in read only mode. To do so,

1. Open Command prompt as administrator.
2. Type the command: chkdsk (driveletter /r
3. If you are asked to recover files, select 'Yes'.
4. If the above command doesn't work try with the command:
   
   Chkdsk (driveletter /f
5. Restart the computer once and check the status of the issue.
6. Repeat the same procedure by replacing the drive letter with E, if the above steps helps you to recover the missing partition.

Hope it helps.

Muralidhar

Microsoft Community Moderator