Warning
Use an administrator account for these steps, and keep a recent backup before making repair or security changes.
What you will achieve
Check filesystem integrity the right way — and know when chkdsk will not help an SSD.
1) Pick right scan type
/scanfor online check./fto fix filesystem errors./rfor bad-sector recovery (slow on HDDs).
2) Run command from admin terminal
chkdsk C: /f
chkdsk D: /scan3) Review results
Read summary after reboot and investigate recurring errors as potential hardware issues.