Lenovo T400, Windows 7, and the 2504 Lenovo Docking Station
If you just upgraded your Lenovo T400 to Windows 7 and have found that your laptop no longer recognizes the DVI port on your 2504 series docking station, here is what you need to do:
1) Download the ThinkVantage System Update 4.0 utility from Lenovo
2) Install the “Intel Chipset Support for Windows XP/Vista/7” package
3) Restart your computer
Now, the DVI port on your docking station will work and you will be able to use two external displays simultaneously.