Hi Ben,

Quote: .....but unfortunately I do not have an XP install disk because I 
bought my computer second hand."

I would suggest to do the following:

Check with the former owner if the XP disc is available.
I should have been supplied with the machine.
Check if this machine has a recovery partition; depending on the built 
time,it either came with a recovery CD or recovery partition.

Check out the info on the following pages
How can I get a Product Recovery CD or DVD?
http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-4M7HWZ

How to use the pre-boot service partition to recover your software
http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-4UFUYK

Lots of info available here:
Overview - ThinkPad T41, T41p
http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-55328

Collect all the relevant drivers from above websites and burn to CD as 
backup.
Create a rescue CD of your present system

I would write more detail,but a lot depends on whether or not you have a 
recovery partition on your harddrive.

Peter E.

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