You need to install your drivers from their website:
Lenovo Support - Drivers & Software (US)
Type in "T43p" on the search page then select your 2668 model, and select Windows XP for the OS and download all the listed drivers, then install one at a time.
If you're still having issues or still have unknown devices, then come back and we can get them manually.
Since you said you already downloaded all available drivers, and are still having issues, then do the following:
Open up Device Manager
On everything that has a yellow exclamation mark, do the following:
Right click -> Properties -> Details tab
Post the following info for each item that has a yellow exclamation mark:
The "Device Description" under the Property drop down
Under "Hardware Ids", it should have something like VEN_####&DEV#### ; post that section, where #### = some alphanumeric combination.
This way we can look up each component individually and get you the correct drivers.