@killyourfm Turned off hibernation?
Admin CMD prompt:
POWERCFG /H OFF
Reboot. Run Disk Cleanup, tick all the boxes, let er rip. Then run it again, click "system files" and do the same again. It'll take much longer.
Run CHKDSK /F. Reboot again.
If that doesn't do it, then resize using Gparted from a Linux live medium, e.g. SystemRescue. Use Ventoy to format a multi boot key the easy way.