Question about CHKDSK

Hi folks , my question is when i run "chkdsk" in normal mode it says no problems but when i run it in safe mode it says errors were found and to do a "chkdsk" with the designation F for fix .

I can never do it right then because it says another process is using it but it says do you want to schedule a check upon restarting your computer which it does.

However this seems to be a re occuring issue and a week later it will say errors in safe mode again.

Any advice would be highly appreciated.