Failed to load certificate file but I can connect to hubs but search does not work

the "failed to load certificate file" is for encrypted connections to ADC hubs, and has nothing to do with searches. I'm guessing you failed at setting Active Mode up properly. You need to allow DC++ access in your firewall / router. There is guides on how to do this. :)

Ok I followed all the guides and I was able to get the computer which hosts the network to work, then did the exact same proceedure for my laptop which connects to the network but this will not work. The only thing I was unable to do from the instructions from DC++ was

'Switch on the UPnP User Interface. To do this: Open "My Network Places", and in the Network Tasks Panel, select "Show icons for networked UPnP devices".

As Windows Vista does not have this option and im unable to find it?

So the only differences between my comp and my laptop are that My laptop is running Vista and the comp is running XP and my laptop uses Norton 2008 antivirus where ive allowed access for UDP and TCP connections and also tried to disable the firewall but no joy,

The computer that connects is not mine so I cannot use this which is why I really need my laptop to work, but cant think why it just wont!!

eMTee suggests this article as an answer to your question:
FAQ #82: “I keep getting unable to register... like, TLS or certificate file related error(s) at startup. Search/download does not work. What should I do?”.