Can I re-partition my C: drive during (for example) factory reset to give it a bigger space allocation?

I keep getting recurring messages on my Dell Inspiron 3793 (purchased new in Jan 2021) saying my C: drive is almost full. When this happens, both Windows File Explorer and Treesize bear this out, last time it happened there was only 151MB free. I wanted to re-install Chrome but the installer failed due to lack of C: space. The SSD (C:) is ostensibly 128GB and the HDD (D:) 1TB HDD, though WFE and TreeSize both indicate only 99GB/931GB allocated.

I've been given the following advice by the vendor (a respectable department store), though disappointingly the manufacturer was not particularly helpful:

"When installing Windows, you can divide drivers as you wish, it should be possible to allow more space for drive C, with Windows updates or drivers updates it may get filled. For example, you have 1 TB storage and you have C: drive 100GB and rest 900 GB is on your D drive, it is possible to change this to 200/800 but I believe you`d need a specialist to change this for you with reinstalling your windows if that makes sense. I have had it done on my laptop as well that is why I am suggesting this option to you"

I'm reasonably tech-savvy, is there any guidance how I can do this? I've twice done a straightforward factory reset of the device, and whilst this gives initial respite of the problem, it doesn't seem to be a sustainable solution. I should perhaps point out that all personal files (Documents, Photos, etc...) are already on my D drive.

Solution 1:

The advice makes no sense: "SSD (C:) is ostensibly 128GB." Since that is faster than the HDD, the OS was installed on the SSD, and that includes program files. Removing 100 GB from the HDD will not help with the primary C:\ drive. You cannot partition that fast 128 GB SSD into a 100 and 900 GB drive, since there isn't that much space!

There are a few things you can do:

• Clean up the C:\ drive.
  • Use Windows Disk Cleanup, including Clean up system files, for the easiest part of cleanup.
  • The WinSxS folder contains older versions of updated files. Clean it using DISM; i.e., Dism.exe /online /Cleanup-Image /StartComponentCleanup /ResetBase and Dism.exe /online /Cleanup-Image /SPSuperseded. N.B. After that, the PC will not be able to revert to an earlier state, before those updates.
  • Reduce space allocated to Restore.
  • Move Documents, Downloads, Music, Pictures and Videos to D:, which you've already accomplished.
  • Though it may be possible to move Program Files and Program Files (x86) to D: to make more room on C:, I do not recommend that, because some applications might not work at all, and all will load more slowly from the HDD.
• Another choice is to get a larger SSD. A 256 GB SSD is more realistic for running MS Windows, and they're available for ~US$30 and up. Check your PC's manual and the SSD vendor's guide for compatibility.