The required installation sequence is (1) Install Windows (2) Install the Intel Chipset drivers (3) install device drivers including the sound and video (4) reinstall application programs and backed up user data.

If you omitted the chipset drivers (and any other drivers) that is probably the problem.

If you didn't install the chipset drivers you can do it now, restart the PC and then install the sound and whatever other drivers you need.

HERE is the Dell downloads for the E520 and Windows XP (Media Center is XP)

fireberd,

I am having the same problem with my Dimension 9150.  I am running Windows XP Pro SP2.  Would you please give me the Chipset link for this machine.

Thanks in advance for your help.

Thanks Fireberd but I have now installed all of the recomended and urgent drivers from the Dell website and still have the same problem. I am bit of a dummy when it comes to PC's and I have no idea what to do now.

I still suspect there is a problem with the way it was reinstalled and/or drivers.  It may take another reinstall, with the correct sequence, to get the problems resolved.   I've seen problems before that took another (correct sequence) reinstall to get them resolved.

By the way, this is really more a Windows XP installation issue than it is a "video" issue. 

repaul, click "support" at the top of this page and you will be able to access the downloads. Use the option for your model number, not the service tag option to access the downloads. 

Next time, do not post in someone elses thread (that's considered Hijacking a thread), instead make a new post.