Whenever you have the subject controllers installed, you must use the Adaptec device driver and NOT the Microsoft generic AIC78xx.sys driver. This applies to all Windows NT 4.0 computers, including SBS and Terminal Server. This also applies to any computer that uses these Adaptec chip sets on the motherboard.
Download the 7800wnt.exe file from the Adaptec site at http://www.adaptec.com/support/overview/aha2940.html. Follow the Adaptec provided instructions. Double-clicking the 7800wnt.exe will install the files it contains.
NOTE: Dell uses a proprietary version of the Adaptec chip. You must use the Dell provided driver from