I'm sure just about everyone here understands what it means in terms of time and money lost for a business PC to be down, but your spending a little more time now to save A LOT of time and headaches later.
It shouldn't take 3 days to do a setup. I just installed XP PRO SP3 on a dell dimension 4600 (P4 2.8 GHZ, 512 MB RAM) that took me about 4 hours to fully configure and that is mainly because the windows updates took 2-3 full hours to install (took seconds to download, I have a 90 Mbps + broadband connection).
You might have a good part of one day into setting it up now, vs two hours the other way but think of it this way. Do a fresh install on new hardware, set everything up, restore her data and then image the system. Now the next time the system crashes you can load the image onto a new fresh drive and it will be like it came out of the box for her.