I found it easier to buy a Win7 desktop, because my XP crashed and died.
Prices on new laptops and desktops are low. You might consider that purchase. XP machines were limited to 4 gb memory (IIRC).
Additionally, you need to check which software and hardware might not work under Win7. I lost several software programs. They were too old and no upgrades or comparable replacements were available. I did manage to finagle a few other programs to work partially or fully under Win7. I also lost an older desktop laser printer because no one created a driver for the 64-bit Windows 7.
Most laser printers are compatible with the generic HP Laserjet drivers.