Most of the shutdown hangs I've seen in Win98 / Win98SE were caused by driver issues. I suppose you could check to see if you have the latest ones, especially video drivers, installed. Also, you might consider what concurrent apps / utilities you have running. Some of those can cause a hang at shutdown. The most likely suspects are Adobe Type Manager, old version of Pretty Good Privacy and some anti-virus software. (Sometimes it's just a particular setting on the anti-virus software that causes such issues.)
Hope you get it sorted out.
Regards,
Jim
BTW, if this is an older laptop that came with Win95 you may have trouble getting the device driver updates you need to make it work with Win98. Since devices are integrated into the motherboard design on laptops, you usually have to depend on the laptop vendor, rather than the device maker, to supply you with updated drivers. It's a perennial problem for laptop / notebook users.