Configure NIC for DHCP
regedit:
o HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\%GUID%
o Select the IPAddress key and double click it.
In the Edit Multi String dialog box enter a second (and third and so on) IP address.
o Select the SubnetMask key and double click it.
In the Edit Multi String dialog box enter a second (and third and so on) Subnet Mask.
Disable/Enable NIC
Windows 98:
This trick can also be accomplished with Windows 98, only there you need to
modify the following registry path (instead of the one in step 2 above):
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans
In Windows 98 you'll also need to reboot your computer for the trick to work.