I'm currently running Client 4.90 SP2 Update D and I'm going to upgrade
to 4.91 SP2 Update A. The question I have is do I need to remove the
existing client or can I just install the new client over top. With
Windows 98 this generally caused problems is it different with Windows 2000?

On a couple of test PC's I tried it both ways and it's been to short of
a period to tell for sure but so far it seems to be working fine. The
install went very smooth loading over top.