If your wife's computer is still working, or you can read the hard drives
from another computer, backup all data before you do anything else. Many
users do not realize that a fresh installation of an OS, and even an
upgrade, can wipe out their data.
It does not make economic sense to replace the motherboard of an old machine
unless it is with exactly the same motherboard so you can reuse memory and
all the same vintage hard/optical/floppy drives and can avoid problems with
incompatible motherboard drivers.
It also does not make economic sense to build a computer unless you know
exactly what you want in a high performance machine, as opposed to an
ordinary desktop box, and are experienced at building and troubleshooting.
There are unbelievable bargains out there in premade boxes complete with
warranties.
Places like Tiger (not an endorsement) will sell older off lease boxes with
XP still installed for not much more than the price of a motherboard.
The best option is buy a new box with an installed OS, which means Vista at
this point in time, and install your existing hard drive in the box or
attach it via a USB enclosure.
If you insist on slapping in a different motherboard that, presumably, is
compatible with your existing memory sticks and drives you may be able to
simply boot into Windows and see if it will install new motherboard drivers.
You may have better luck if you first boot into safe mode and delete
pre-existing drivers. However more often than not a new motherboard and new
drivers needs a fresh installation of the OS or the system will be too
unstable because of a bad driver mix.
If you get the old installation of XP to work on a new motherboard you will
have to call the Indians who have American jobs courtesy of Microsoft and
beg for a new activation key anyway.
