OK. Chipset Driver Version 6.1.0.1008 (!) for Windows 2000 / XP from the Lenovo Driver page works fine for Win 98SE.
Now I still need the video driver. Will try the Windows 2000 version ;-)

Yeah maybe was a mistake to buy such a "brand new" ThinkPad to use Win 98. But you know one thing, I haven't used Windows (in virtual machines only) since years so I wasn't aware of such stupid driver issues since the newest Xubuntu Linux 14.10 runs perfect on this notebook. It is a shame ! Still ca...

Just purchased a used ThinkPad X41. Very nice notebook and came in an excellent condition. It is (nearly) more nice than my X61 ones. Don't understand why there are no new ThinkPads like these X41 and X61. But this is an other discussion whićh I don't want to start now. I installed the latest Xubunt...