Windows XP or upgraded OS?
If it is one of the older IBM T series and windows has black listed the driver sounds like the OS was upgraded. The windows xp drivers for some of the audio chip sets are not MS Vista and 7 certified and you have to force their usage. It is possible that the driver is being excluded by the OS at boot if you are using either Vista or 7.
If you are using either Vista or 7 first try disabling the certification checks at boot. You can do this by entering the windows boot loader with f8 just after the bios boot and before the os loads. You have to be quick and sometimes it takes several tries. Then use the option to not do driver security checks.
I have to do this every once and a while with a belkin wifi N card that does not have a so called "certified" driver.
If your audio chipset is an older ac97 chip from analogue devices that has all sorts of laptop specific settings that worked with XP but are now not completely updated to Vista or 7 this might just be the case.
I looked into putting 7 on my t42 and found that I would have to force the OS to use the old IBM XP driver if I wanted the laptop audio to function completely as it was built.
Update: The Lenovo site now has updated driver packages for just about everything including the ubiquitous ad1981a audio! It will work with Windows 7. Cudos to Lenovo for keeping things going on the really good old hardware. I have stuck a 160gig drive and 1.5 gig of ram in my T42 and because it has 2meg of L2 cache it is not that much slower than some newer hardware. In fact it is better than some new cheapo Win7 based netbooks! Now that the pcmcia audigy2 zs super card from creative is fully supported with asio drivers for windows 7, I am very tempted to get an oem of Windows 7 for this laptop....just completely forget using IE and stick with a real web browser and I should be fine.
I guess that Microsoft and Lenovo are starting to realise that some people are getting really sick and tired of the upgrade treadmill and having to ditch good gear every 4-5 years.
Here´s to the
government of BC for giving away all this great gear last year for next to nothing at their surplus warehouses..I got this t42 and a docking station for less than a hundred bucks!