how can i delete permanent files?

i am running on windows 98, i recently downloaded a software and install it into my pc. After i uninstall the software, some files are not deleted thus i delete the files manually.

my problem is there are files that can't be deleted and they stays in my hard disk permanently.

how can i delete the files that stays in my hard disk permanently?

What error do you get when you try to delete them?

you could always go into DOS and delete the files there if windows wont let you

thanks, i could delete them now...