22H2 Update--Not enough diskspace?

[CarlAlessi]

I have indications in my Registry that this update is unavailable due to lack of disk space. 

• The "RedReason" key indicates "SystemDriveFull".
• The "SystemDriveTooFull" key has a value of 1.

This is puzzling because my C Drive has 282 GB free. How much free space is really necessary for this update? Is a safe remedy to manually change the keys that I cited so that the update can be downloaded and installed?

Thanks,

Carl Alessi

[#2]

We have the same problem: SystemDriveTooFull = 1 on some workstations, but the workstations have about 200 GB of free space.

Last readiness scan was today.

How do I fix the problem and let Windows 11 install?

[#3]

In scope of opened support case in Microsoft we identified the root cause of the issue: System Reserved Partition must have at least 15MB of free space. In my case SRP has 16BM space in total 😃

[#4]

Please ignore my last comment above. I pointed to wrong partition name.
The issue "RedReason" = "SystemDriveFull" you may see in WUfB report (update compliance) means that a UEFI partition on device has less than 15 MB of free space. Typically, free space in the UEFI partition is occupied by BIOS update files.
Windows can’t remove outdated files on its own. Thus, to fix the issue, you have to mount the hidden UEFI partition and remove the bios update files manually.
In my case I removed whole HP folder from the mounted partition.
Don’t forget to unmount the partition back.
Afterwards re-start compatibility scan.

[#5]

@DinarGalimov_person Thanks for the reply. In the end, I simply swapped out my 1TB hard drive for one that I purchased quite some time ago that's 2 TB.  That enabled me to go in and enlarge the UEFI partition to a sufficient size that enabled me to eliminate the problem.

Carl

[#6]

Windows may be looking for additional free space to ensure that the update process doesn't conflict with system files or folders.