All we need is an easy explanation of the problem, so here it is.
I have 1TB HDD with 800GB free space plus a typical System Reserved partition.
I removed system files before shrinking in Disk Management since suggested shrinking size was no more than 100GB
- system restore
- debug info
- disk clean up
rebooted and performed defrag in c: -> properties -> tools
That gave up to 800GB available shrink size, but still shrinking it in Disk Management to suggested or smaller amount results in
There is not enough space available on the disk(s) to complete this operation
It worked shrinking off small amounts like 100GB
How to solve :
I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.
Use GParted. It sounds like you are trying to shrink an actively running operating system. You generally cannot do this unless you have already split this 800GB chunk off into a partition that is separate from the active OS.
Edit for added details:
You will need to use GParted to do the shrinking operation since that partition is the active OS. Also it would be a good idea to leave approximately 40GB or so of buffer space on the Windows partition just in case.
Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂