This problem has kept me bugging for over half a year now! I've tried to reset my old Dell Dimension 8250 desktop and installed a decent release version of Microsoft XP Professional OS version. (I've got MSDN.) However, most of all drivers for the motherboard I've downloaded from the Dell support website don't work and I've figured out that this might be due to the OEM version of the initially pre-installed OS. Further, Dell seems to have those motherboards produced by themselves: http://www1.shopping.com/xPO-Dell-Dell-Dim-8250-Motherboard-E210882-Dimension-w-Tray. Now, I've been looking for the appropriate ethernet controller driver for a normal OS version on the Intel website ever since. There are so many and all those I've tried so far haven't worked, http://downloadcenter.intel.com/filter_results.aspx?strTypes=all&ProductID=827&OSFullName=Windows*+XP+Professional&lang=eng&strOSs=44&submit=Go! and http://downloadcenter.intel.com/filter_results.aspx?strTypes=all&ProductID=828&OSFullName=Windows*+XP+Professional&lang=eng&strOSs=44&submit=Go! in particular.
Does anyone know the correct Ethernet drivers for this motherboard or can confirm that there's none at all except for those offered on the Dell support website which again, only seem to work with a Dell OEM OS?
Since this is an OEM product, I would recommend that you contact the manufacturer for further support. I think they should be able to clarify this for you. The download link that you have gone through are the Intel boards that have the 850E chipset and which have the 82562ET lan controller as optional. Hence the drivers from this link may work if the board have this ethernet controller.
But OEM, they do modify the hardware on the boards physically, so if there has been some modifications, then they are the only one that will be abe to help you.
That was my first approach, of course. But Dell Technical Support couldn't help me themselves. Heck, I've spent around 6 hours contacting those guys who just sent me through all different kind of departments. Obviously, the computer model is rather old and out of warranty. The farest I've got so far in such cases was some illuminous guy in Poland who offered me a download link at intel.com for 50$. No version numbers, no NIC information - they seem to know or want to know nothing. (I've even got some of my questions deleted on the Dell Forums because I had pointed out this daylight robbery methods as I consider them. If forum members want to know what approaches I've already taken, I tell them, of course.)
Now, I've gone back to my parents' place today and found the old OEM version, installed it all according to handbook, but even then, the driver provided on the Dell website doesn't work. It ends in an installation process in which at 100% a DOS-window called brnvdst.exe or something flashes up for a split of a second before the whole process gets aborted.
Well then I don't know what else to advise you.
According the drivers you have tried from the intel website, I was assuming that you have either of the two intel motherboards with the 850E chipset, but this does not seem to work. They may have modified the hardware on the board as I stated earlier or it could be that the on-board lan is damaged.
Even from our side here, it seems that you have done quite some research to try to find the correct driver but with no luck. Not many people would have been able to digg out and find the links that you found for the two 850E chipset motherboard and tried their drivers.
If not I would have advised you the same, but you already did it. Hence I don't have any idea what else I can recommend you.
If there are any other people out there who can offer some advice on this thread, it would be great.