Windows and Routes
To make a route on Windows semi-permanent (it will survive a reboot) simply append the -p command to the end of the route command:
route add 1.2.3.4 mask 255.255.255.0 2.3.4.5 -p
To remove the same route simply use the -p again so it’s not persistent:
route delete 1.2.3.4 -p
Check to make sure they’re removed in the registry at:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\PersistentRoutes