What's My Thinkpad T40's Problem?

I own a Lenovo Z61m (bought 2006) as my main laptop, but I still used my T40 (bought 2003) as a backup.

Recently my T40 began having problems. I tried to restore it to its original Windows XP Pro settings via the Access IBM button, but the whole thing crashed and refused to work.

I changed the BIOS to boot from the DVD drive, and tried installing Linux onto it (to save money -- why buy a new operating system for a 2003 laptop?), but always got errors messages (that vary) partway into the installation.

Messages like:

The following file did not match its source copy on the CD/DVD/target/lib/firmware/atmel_at76c503-rfmdaccbin

Or:

[Error 2] No such file or directory:'rofs/var/lib/dpkg/info/hplip-data.nist'

Or:

ERROR 5 INPUT/OUTPUT ERROR

Or:

ERRORS FOUND IN 52 FILES

Some of these errors suggest I might need to clean the DVD or DVD player, but I tried 4 different Linux DVDs; three Ubunto, one Fedora. Two were newly bought, pristine Ubunto DVDs, the other two were scratchy DVDs borrowed from the library.

Eventually I replaced the hard drive with an 80 gig Hitachi Travelstar, 7200 rpm. The problems persisted.

So I replaced the DVD optical drive. The problems persisted.

So I bought a new copy of Windows XP. The problems persisted.

Now I have a 2003 Thinkpad with a brand new hard drive ($120), DVD drive ($50), Windows XP Pro ($50), and two new copies of "free" Ubunto Linux ($30). And it still doesn't work.

A friend suggested I need to update the BIOS firmware so it recognizes the new Hitachi hard drive. I don't know how to do this, or if that's the problem.

Anyone know how I can I fix my T40?