I checked the event viewer and here is the result. My Windows Server 2008 is in Spanish so I will do my best to translate the messages.
**** System Event Viewer entries:
1. The service ATICDSDr could not be initiated due to the following error:
The download for the controller has been blocked.
2. Aplicattion : : \??\C:\Users\ADMINI~1\AppData\Local\Temp\{9B94B~1\atiicdxx.sys failed to load
3. Loading of \??\C:\Users\ADMINI~1\AppData\Local\Temp\{9B94B~1\atiicdxx.sys was blocked due to an incompatibility with this system. Please contact the software manufacturer to get a compatible version of the driver.
**** Security Event Viewer entries:
1. Integrity of the code determined that the hash image of a file is invalid. The file could have been damaged by an unauthorized modification or the invalid hash could indicate a posible error in the disk device.
So, maybe the problem has nothing to do with privilegies but it is a safety procedure in order to avoid installing an incorrect/damaged driver.
I tried running a driver update for the network card and I get a different message: No devices present.
So, what I see is that maybe the drivers I have tried so far are not the correct ones, although I do not have an explanation for it because I downloaded them from DELL Drivers and Downloads site using the Service Tag in our server. My main concern is about the BIOS update because, if it is not correct either, I would not like to get into trouble with it.
I highly appreciate your support and service. Please let me know about any comment you have about this issue.