Does this computer work at all now? Can you boot into the operating system? What version of Windows do you want to install?
Do you have access to an external CD rom drive?
This is from the IBM/Lenovo description of this model:
“The IBM ThinkPad X31 also offers the Access IBM button, a “portal to IBM support” that taps into a rich set of onboard resources, diagnostic tools, automated solutions, and links to updates and service on-line. Another ThinkVantage technology, RapidRestore PC, provides one-button disaster recovery that can restore previously saved data, settings and applications after a software failure.”