In the recent thread "Lenovo T43 (with XP) Wont Power On", I mentioned
that my old Lenovo T43 died. I have given up on fixing that computer
since it's obvious the motherboard is shot.

I bought an identical T43 from ebay, and it is identical, except it came
with 1gb RAM (my old one had 512mb RAM), and a larger HDD. (80gb,
instead of 40gb).

The computer arrived and had XP Pro SP3 installed. That booted up
immediately, and the computer works fine.

The plan was to insert my old HDD, so I could use use it as I had it
configured, with all my software ready to go.

I pulled out the new HDD, and put in the one from my old computer. It
refuses to boot.

That old drive has XP Pro SP3 on it as well.

In Normal Mode it just went to a blank screen and hung there. I get a
whole screen of words saying there are hardware changes. (No ****). But
it's the same model of computer with the only difference being double
the RAM.

I then tried to boot to SAFE MODE. I get a whole screen of text similar
to:

multi(0)disk(0)rdisk(0)partition(1)\Windows\system 32\drivers\xxxx.sys

and many more lines like this. It hangs when it gets to Mup.sys

How do I get this to boot?

Note: I had a dual boot setup on that drive, where I could also boot to
Puppy Linux (installed on the HDD). That's just there mostly so I can
backup (direct copy) those XP files that cant be copied while XP is
running. (These T43's dont allow for USB booting, so I just installed
Puppy Linux on the HDD).

Anyhow, Puppy Linux boots right up, and all my files on that drive are
available, so I know the drive is working.
The drive is formated to NTFS.

I'd really like to get back my original installation from the drive that
came out of the old computer. How can I get it to boot?

Reinstalling is an option, but I'd prefer to avoid it.

The HDD that came with this computer came with a clean copy of XP Pro
SP3, but I have never trusted using an OS installed by someone else, for
reasons relating to malware. It did come with AVG antivirus installed,
but also came with things like Google Chrome which I dont want.

What can I do???? Thanks!