Why can't I shrink the SSD to the desired size?

Hi,

Could you please post the Disk Management picture, if you have another partition at the end, creating another partition is slightly difficult, you have to move the partition at the end(in my case 1GB) to next to 250MB Healthy EFI partition, to achieve that you need a third party program like MiniTool Partition wizard Free, you need to have the C partition at the end.

You need to backup your system with a familiar program to be on the safe side, in case anything goes wrong, you can go back to the stable system, then follow the instructions for how to move the partitions to a desired position.

https://www.minitool.com/partition-manager/partition-wizard-home.html

https://www.partition-magic-manager.com/partition-magic/how-to/ResizePartition.php

https://www.partitionwizard.com/clone-disk/windows-10-move-recovery-partition.html

Yes, I have used MiniTool Partition wizard in another laptop in the past, but not in this laptop because I don't need to create another partition, so it's safe but you have to prepare yourself well in advance, like getting familiar with the procedure and backing up your working system to another external drive, recovery disk to recover the backup, I cannot guaranty that it won't mess up the system if you don't do it properly because you are the one going to perform the act, I can clear any doubts you have and give you other useful information.