Why my computer keep running disk check/CHKDSK?

Every time I turn on my computer (HP laptop running Vista) it start running disk check. Also if I let it do the check the next time I open my computer it'll do it again. I also tried to schedule a check hoping that after it'll finish it the problem will stop but with no joy. Also, when I try running safe mode it stops at a file named something like diskcheck.sys?