E5400 - problems with Video driver and output to external screen

Hi, 

I ahve a brand new Latitude E5400 provided by my company with XP SP3 on it. 

As I had issues when connecting an external monitor, it was flicking, I have installed the latest Video driver which I have downloaded a few day s ago from Dell web site. 

Now, it is much better, the output to the external monitor works better but: 

* the intel video graphics driver has "disappeared", I don't see the special tabs or context menu or special GUI it had created. Unisintall and resinstall has not changed anything ! So I have the standard control panel of Windows XP

* each time I reboot the laptop and connect the monitor again, I have to setup again the monitor resolution and colors. 

My IT guys do not know how to solve this. 

Do any of you have faced the same situation ? 

any idea how to sort out this problem, and/or how to fullly uninstall the driver so it can install correctly again ? 

thanks, 

L