If the old desktop does not have Wifi in it which I suspect it doesn't, you'd need a cable to hook it up to the router directly.
Win 98 is really old... old old...no more updates for it etc. It would be highly vulnerable on the net today. It is probably low in RAM and would be very slow doing everything.
You could upgrade it, but Jo would have to help with that.
Win7 upgrade is about 80-100 dollars. You might need more RAM to run it too.
This desktop of mine is running Windows XP with 1 Gig of RAM and that is not enough these days. Thinking about more in fact!
__________________
All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
************************************
.
Weezie looking at petunias 8.25.2017
****************************
These forums are for mutual support and information sharing only. The forums are not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider. Always consult your doctor before trying anything you read here.