Ha....
It took me a good amount of time to find out which version of OpenVPN is supported by Windows Vista. Went thru all forums and blogs but no use. My laptop was throwing me challenge each day. Atlast OpenVPN release candidate 22 from version 2.1 on 2009.11.20 fixed my issue.
http://openvpn.net/release/openvpn-2.1_rc22-install.exe
support.real-time.com
