how long is suppose to take?

ive run it as sfc/pergecache then i am running it as afc/scanonce ,and rebooting.

its been at it for about an hour and a half , and not even done 25%

very little running in background (no a/virus etc)

is it supposed to check each individual file by compering it with a flash (on the cdrom) or at least it seens like that.