You might also make sure you've cleared all your temporary files (look in windows/temp), deleted your browser cache and emptied your recycle bin. I've seen systems with literally tens of thousands of temp files cluttering up the system. Then run scandisk and fix any problems. Then system file checker. Then defragment. If this doesn't improve things then reinstalling the OS might be your option of last resort.
Need to copy (NOT move) all documents out of My documents folder and put into a new folder as if directory entries for files and folders exceed 32k windows 98 will open folders very very slowly. I think its called an undocumented product feature in Microsoft speak.