two methods
First, use DOS commands (immediate effect)
Second, modify the registry (restart to take effect)
1. Open SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards
RegOpenKeyEx(HKEY_LOCAL_MACHINE,"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards",0,KEY_READ,&hKey)
2. Remove all subkeys under the open registry
RegEnumKeyEx(hKey,dwIndex++,szSubKey,&dwBufSize,NULL,NULL,NULL,NULL)
3. Open the subkey
RegOpenKeyEx(hKey,szSubKey,0,KEY_READ,&hSubKey)
4. Get the ServiceName of the network card
RegQueryValueEx(hSubKey,"ServiceName",0,&dwDataType,szData,&dwBufSize)
5. Open the new registry according to the network card ServiceName
RegOpenKeyEx(HKEY_LOCAL_MACHINE,“SYSTEM\\CurrentControlSet\\services\\”+szData+"\\Parameters\\Tcpip",0,KEY_ALL_ACCESS,&hLocalKey)
6. Modify the local network information
//IP
RegSetValueEx(hLocalKey,"IPAddress",0,type_ip,"192.168.123.123",dwIPSize)
//SubnetMask
RegSetValueEx(hLocalKey,"SubnetMask",0,type_SubnetMask,"255.255.255.0",dwSubnetMaskSize)
//GateWay
RegSetValueEx(hLocalKey,"DefaultGateway",0,type_GateWay,"192.168.12.1",dwGateWaySize)
