Question: You said "under Windows 98." Just to make sure, are you running Win98 or running WinXP and using compatibility mode or a Win98 emulator?
Assuming you are, in fact, using Win98, then my next guess is a bad install. Make backups of your saved games, then try an uninstall/reinstall of the game. Finally, move your saved games back into the appropriate spot.
Note: Certain types of installation glitches can also corrupt saved game files. First try an uninstall/reinstall and attempt to load one of your old saved games. If it still takes forever or hangs, then try starting a new game and do a save/load at the first available opportunity and see it THAT takes forever to load. If reinstalling the game makes your old saves hang but lets a new one work then you know it was an installation problem. If you try this and even the new saves hang during loading, then it is more likely either a hardware or driver problem.
Time flies like the wind. Fruit flies like bananas.