Thawte personal email certificates

I just created and installed a certificate for the first time. Is it
possible to install that certificate on a second computer also? The Thawte
help info doesn't seem to address this and I'd rather not wait a day for
their answer to my question.

My home and office computers both run Win XP, OE is the email client on
both, and I use the same email addres on both.

Thanks in advance.

George