On Windows, my logs from the BolehVPN client have this error: "All TAP-Win32 adapters on this system are currently in use"

First of all remember that you can only be connected to ONE configuration at a time. You should also uninstall all previous OpenVPN based VPNs that you have used before installation BolehVPN.

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 and BolehVPN
4. Restart OpenVPN/BolehVPN
5. Retry reconnecting

Check 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 disabled

If there is no TAP-WIN32 network connection in your Network Connections

1. Browse to where you installed BolehVPN
2. Double click on deltapall
3. After that completes, double click addtap.
4. Restart BolehVPN and try connecting

If this doesn't solve it, uninstall BolehVPN and reinstall it and do a clean reboot.