Re-install Vista H.P 64-bit version

Hi all,
I need to re-install vista because I cannot get the printer software to
install properly (network printer). I built 2 identical machines running home
premium 64-bit, had to wait several weeks to get software that was compatible
with vista and had a successful install on one machine with no problems but,
the other machine will not communicate with the printer. Does see the printer
in networks, just will not communicate with it. Thought I must have done
something or something happened to cause this issue. I figured if I
re-install Vista I might be able to clear this up. But, I see there might now
be an issue with re-activation. Can anyone advise me on this

Thanks much,
Mark