I did a clean installation of Vista on a T43 recently. I hope my experience could help those who want to give Vista a try.
I have an IBM T43 and a Vista Business DVD (final version) in hand. The T43 was runing Windows XP and all sort of Thinkpad utilities from factory retored.
First I reboot the machine from the Vista installation DVD. The installation program said it found a pre-installed old OS on C: drive. Instead of asking me to repartition and format the hard drive as any other OS would normally do, it simply moved "Program files", "Documents and Settings" and "Windows" to a directory, namely "Windows.old". Then the installation went smoothly and finished by asking for a few common inputs, such as user name, password, language, time zone etc.
When Vista boots up for the first time, I notice it automatically recognised almost all devices and installed drivers for them, except for the integrated sound card. However, the automatic upgrade program immediately alerted me that some upgrades are availble from Microsoft. I leave it to download and install the patches. After another reboot, the sound card works.
Now you may wonder how my T43 survives without those Thinkpad utilities. Well, I simply downloaded and insalled "ThinkVabtage System Update" program for Vista from Lenovo, and ran it to retrieve all necessary utilities for Thinkpad. After a few minutes and another reboot, all old faces are coming back under Vista without a single problem.
Finally, I can't get the glass experience due to Intel 900 integrated graphic chip, still I would say Vista is beautiful and seems to be faster than XP with only 1GB ram. PM-750 1.86G CPU and 5400 RPM hard drive. Well of course, it consumes more memory than XP: 400MB for the syetem only, while XP eats about 200-300MB.



