you need to go this link to do as tutorial , this will help you
https://forums.openvpn.net/viewtopic.php?f=7&t=7806
1 rename the internet network card and openvpn netword card so it makes thing simple
click search type ncpa.cpl and press enter , click the the internet network card and chose properties/chosing share tab, tick allow other netword user connect through this computer internet connection.
choose openvpn netword card if it is present and click ok.
right click openvpn netword card and chose properties chose ip4 and set its ip as 10.8.0.1 subnet mask 255.255.255.0
open your openvpn config add this line
"i p-win32 manual "
open regedit and find
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
charge IPEnableRouter =1
this will make windows will lan routing all network card
go service and choose Internet Connection Sharing and choose automatic
go to service and find routing and remote access and choose automatic
after that restart computer and check every service have been start so your openvpn run at windows will routing all over network card and client can go
so make sure go to service to check everything work and check
remove this lines . some line only for Linux so on window it have nothing
push "topology subnet"
user nobody
group nogroup
