On guildwars.com there's a support page, when I got to there I typed in error 5 in the search box and got this:
"We're sorry that you are experiencing network difficulties. The error you are reporting, Code=005 (NET_ERR_CONNECT_FAILED), is indicative of a mis-configured network setting or network interference. Please use the following information in order to assist you in troubleshooting this issue:
1. Make sure GW.EXE or GWSETUP.EXE is added to your firewall's exception list. If you have already allowed Guild Wars in the past, please double check the exceptions. Often times firewalls will decide to block Guild Wars after it has patched. If adding an exception does not help, please try completely uninstalling the firewall software.
2. If you are using a router, please open and/or forward both TCP port 6112 and TCP port 80 within their settings. If you are connecting to Guild Wars while on a campus or business network, please consult your network's administrator to verify that these ports are available."
http://uk.support.plaync.com/cgi-bin...&p_to pview=1
I forwarded port 6112 to my pc, seeing as I'm behind a router and I'm not using a firewall or anything, so far I haven't gotten the error, so I hope it stays this way.