You want to be to have Terminal Services installed in Remote Administration
mode on a Windows 2000 server. This gives you two administrative sessions
besides the console session, which can be used to run such admin tasks.
From the workstation perspective, if you have XP, there's nothing to
add--just run Remote Desktop Connection.
If the workstation is something else, you'll need to add the RDC. It's
downloadable, and small--you can, in fact, fit it on a floppy, I believe,
but it is a stretch.
I do this quite regularly in just the kind of circumstance you mention.