Yes, you do. Some programs will seriously misbehave on Win98 if the swap file is disabled, regardless of the amount of free memory. Proof:

I've just wasted about an hour trying to get Sanitarium to work. The game consistently got stuck after the intro sequence in a weird way: the background ambient sound kept playing normally with the first few milliseconds of the voiceover being stuck in a loop over it. At this point only a hard reset helped. Tried all sorts of updates, NoCD cracks, etc. to no avail. Then in my desperation I thought, hey, what if I re-enable the swap file? Bammm, the game started working right away flawlessly!

After this I ran into another game, Nocturne, that seems to run fine with the swap file disabled (only tried it for about 5 minutes, though), but it informs you in no uncertain terms at the start screen that this is in fact a very bad idea, and the game needs at least 200 Mb of virtual memory, otherwise you might run into stability problems.

I have 512 MB RAM in this Win98SE box, so I disabled the swap file as a misguided attempt to prolong the life of the SSD. But then I'll only use this machine a few hours per week on average (well, long term it will be probably even lower than that, to be realistic), so who cares about the life span of the SSD, really... A 120GB SSD costs like two lunches these days (quite cheap lunches, actually). And I'm not gonna live forever either 😀

Office 2000 is one program that misbehaves when swapfile is disabled so I make a tiny one just so that it wouldn't barf.

This thread is very old, the OP solved their issue in 2018 and anyone who knows what they are doing knows that a swap or page file is needed for proper operation of Windows.
Thread is closed and will remain closed.
If further discussion is necessary then open a new thread and link to this one.

Since it appears I need to elaborate further: This thread is not a repository of knowledge. This thread was where a user asked for help and then received it. If you wish to have a "knowledge or guide" thread then create one but do not hijack a thread because you can't be bothered to create a new topic. This is not a new thing for vogons so should not be a surprise.