Hi I have 3 separate hard drives. 1 drive has Windows 2003 Sp2. Second drive has Windows 7 RTM 64 bit. The third drive has Windows Vista business 64 bit sp2. When I boot to Windows 2003 server I have no problems, I do what needs to be done, internet ok, can add users, no problems. It is given a static IP address etc. Then when I reboot my computer to the windows 7 hard drive, I then change from static to dynamic or automatic IP, then my NIC refuses to work. I cannot get it to connect to a local network or the internet. The NIC will not let my Netgear router, which is acting as my DHCP sever give it any IP or other info. Even if I set a static ip address it will not work. It insists that it gives itself it'own IP address. I will then boot to my separate Vista drive and I encounter the same problem. The only way to fix this problem is to uninstall the Realtek RTL8168c(p)811c(P) Familly PCI_E GBE NIC driver and reinstall it ON BOTH THE VISTA and the WIN7 Operating system. When I am on the Win 2003 Server the other 2 Hard drives are not connected to the computer!!!. Also when I first boot to Win 7 (after using win 2003) I have reset the router to factory defaults. The router is a Netgear DG834PN (I am not using wireless) This seems to be some sort of driver problem. I have found that the IP lease is locked and reads 1/11/1970, and lease runs out 1/11/1970. This is very odd. I am striving to understand what is going on. Any help would be Great. Thanks