can i upgrade an ibm t20 with windows 98 to windows xp?

Well since support for windows XP ends tomorrow, i wouldn't recommend it. Also, that is some antique laptop you have there! I'm suprised it's still running. My advise would be, leave it as it is, it isn't going to be any better.
 
How much memory / hard drive you have there? Is it Win98 (as in the title of the post)l or Win95 (as in the body)?
Even if you are able to isntall XP, I doubt you will find drivers online. So, your best bet would be (if you go this route) to find out XP with integrated SP3.