You have two seperat posts, both of which are very vague. Why not delete one of them, and try to describe your problem in such a manner that we can understand, and hence, may be able to help.
As far as I know, Killbox doesn't work with Win 98. It uses a pendingFileRename registry entry that is not available in your Operating system. If you want to delete files on reboot, then your best option is to use a wininit.ini file. But I don't want to suggest anything until I have a better idea of what issues you are having.