In **Control Panel / Administrative Tools / Services**, make sure that the **DHCP Client Service** is started.

If the above fix doesn't work, then it's possible that the TAP-Win32 adapter is being firewalled. In general, it's safe to disable the firewall on the TAP-Win32 adapter because OpenVPN ensures that only an authenticated machine on the other end of the connection can communicate through it. However, there have been reports that certain third-party firewalls will block the TAP-Win32 adapter after an XP SP2 upgrade.

You can also try changing the `ip-win32` setting to a non-DHCP method. For example:

For more information on managing tap-windows drivers, look [here](/Pages/Managing%20TAP-Windows%20drivers).