Some times when you change your network card, the last IP configuration is not clean, and when you trying to set the new IP address, you receive and error similar to:
The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter Name of adapter….
You try following steps to remove all IP configuration:
1) Open the command line, type in run programs cmd, and press Enter
2) Type set devmgr_show_nonpresent_devices=1, and press Enter
3) Type devmgmgt.msc, and press Enter
4) Select View > Show Hidden Devices menu
5) Go to tree view and expand network adapters
6) Select the all network adapter
7) Right Click and select Uninstall
Next time, you do not have any problem to configure your IP address
Also you can review other details in http://support.microsoft.com/kb/269155
