find bootdisk for win98se at www.bootdisk.com then make a disk bootable. after that shutdown and restart the computer with the disk in. Now you are in command.com and can edit or delete the files you need. you should know the location of the files you want to delete so you can navigate to those directories to delete them. you should also be familiar with some dos commands to help you along.
CD space and the direcories name = move to that directory
cd/ = gets you back to the root directory
dir/w = lists the directory
del and name of file = deletes file and directories
copy and file name = copys files
deltree and name = directories and files
edit and full name = edit files
mkdir and name= make a directory
rd and name= remove directory

there are alot more commands but these should get what you want to do.