First of all remember that you can only be connected to ONE configuration at a time.
Try these three things:If you are using Windows 2000
Install OpenVPN 2.09 instead which is available here
.Make sure you aren't already connected to another VPN
1) Double check this!!!!!Ensure you have no duplicate processes
1) Press ctrl alt del
2) open task manager
3) End all instances of openvpn-gui and openvpn.
4) Restart OpenVPN
5) Retry reconnectingCheck if your TAP-Win32 Adapter is disabled
1) Go to Network Connections (Usually can be found in your Control Panel)
2) Make sure your TAP-Win32 network connection is not disabledIf there is no TAP-WIN32 network connection in your Network Connections
1) Start, Programs, OpenVPN, Utilities
2) Click on Delete All TAP virtual ethernet adapters
3) After that completes, click on Add a new Tap Virtual ethernet adapter.
4) Restart OpenVPN and try connecting
Check if your OpenVPN installation is corrupted
If this doesn't solve it, uninstall openvpn and reinstall it.