Unfortunately, the last time I used 98 was so long ago that I can't remember if it works in the same way as XP. I think it does, so I'll just try to clarify the instructions I gave for XP and you can give it a go.
Look at the task bar. At the left end is the Start button, and at the right is the system tray (with the clock and possibly a few other things.
Place your mouse over the clear area in between, and click and hold down the RIGHT mouse button. A menu should appear. One of the items on the menu should be "Lock the Taskbar". If it has a tick by it, that means that the taskbar is currently locked - click on it to unlock it. If there is no tick, it's already unlocked, in which case just move the mouse to a clear area of the desktop and click the LEFT button to get rid of the menu.
Place the mouse over the middle of the task bar again, and move it slowly towards the top edge. When it is directly over the edge, the pointer will change to a vertical double-headed arrow; click and hold the LEFT mouse button, and move the mouse up the screen. As you do so, the taskbar should get bigger. When it's the size you want, just realease the mouse button.
It may be that in 98 there wasn't an option to lock/unlock the taskbar, in which case it won't appear on the menu, and you can just follow the instructions in the last paragraph.
I hope this helps!