Windows 10: Why was my C drive partitioned without my OK?

I am using Windows 10, and my C drive partitioned D: New Partition without my OK or notification.The only suspect I have is I used MSFT link to determine if my PC could run Windows 11.It does not qualify.I notice EFI appears as a System partition in Disk Management window, and if it UEFI contributed.File Explorer now displays >OS C: New Volume D:How can I return my C drive only one partition?

:)

 

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

 

Unallocated Space to C Drive

Thanks

 

Partitioning of C Drive

I have 210 GB free space with a C drive of 251 GB. I have been trying to create a separate partition of 100 GB and 151 GB will be left on C drive. I find that shrink volume is only 1.50 GB. Pease help me if it is possible to partition and what steps do I need to follow. Thanks.

Purshotam