Error 2010 is very infamous among older T-Series ThinkPads.
Generally, this is because the hard drives you are using are not in the very specific list of hard drives the BIOS looks for. This isn't necessarily a problem, and if your computer is running fine, you don't need to fix it. If you want to, here's how...
The easiest way to fix this is to get a hard drive that comes packaged with the T43's. Easy fix, but hard to come by. Certain hard drives can get a firmware fix, but very few of them will make a difference. A good fix would be to use a modded BIOS (don't worry, it's identical to normal BIOS without the 2010 error). Before you do anything, I suggest you take a look at the bottom of your laptop and find the TYPE XXXX Sticker. You NEED to know this number when you download the upgrade for your BIOS. Here's the site where you can find all of these solutions. Choose the proper link with your type number on this site.
http
/www.thinkwiki.org/wiki/Problem_with_non-ThinkPad_hard_disks
NOTE: IT IS ESSENTIAL THAT YOUR LAPTOP/BATTERY DOES NOT GET UNPLUGGED AT ANYTIME DURING A BIOS UPDATE. FAILURE TO FOLLOW THIS MAY RESULT IN A LOSS OF SYSTEM FUNCTION!
Make sure you know where the download link is, avoid malware. It's a .zip file you are looking for. Extract all files to a folder that you specifically create for these files only (name doesn't matter). Run the file with the "BIOS" icon next to it. You don't need to change anything, just click flash. If you downloaded the wrong one, though, you will get an error message part way through, and you will have to redo this. If all goes well, your computer will restart and you will not have any more 2010 errors.
A guide for this process is currently underway at Ifixit.com , which will contain pictures and specific steps.
Hope this helps, if you still need it!
Nate