Scandisk hangs in Dos mode

I have a win98 PC with 20GB Hdd, when I started my PC this morning the message said that windows was improperly shutdown. But the evening before I had shut it down properly. Now Scandisk hangs when running in dos mode. It cant seem to get past this.I have had odd disk problems before but a scandisk did not show any errors??. could it be that the disk is failing??, or is there another solution?