A really slow bootup after installing a nic usually happens because Windows binds the TCP/IP protocol to the nic by default. Also by default, TCP/IP gets set to obtain an IP by DHCP. If you're not on a network with a DHCP server, it takes a really long time out. To avoid this problem, either remove the instance of the TCP/IP protocol that's bound to the nic in your network configuration, or assign it an IP.