After installing a wireless a router and installing and running Grisoft's AVG (which quarantined hundreds of threats and deleted 8)I tried to startup of a Dell XPS 400, the XP screen goes to user accounts, but won't allow a user to click on account. Using safe mode, device manager shows a yellow exclamation point on a PCI Device. It also shows PCI bus 0, Device 27,function 0 and Error Code 39 which says device driver may be corrupted. I then went to support.dell.com and entered the service code and downloaded the ATI Hyper Memory PCI Express twice. Dell's response to me now is to replace the motherboard. What does the message from device manager mean? What does that indicate to you?