If the network works in safemode with networking then the problem is almost certainly an issue with a program or service that is running at startup and causing the problem. Take a look at this article and see if you can take the steps necessary to identify the offending process
http://support.microsoft.com/kb/929135/
It can take a while, but the best thing to do is a step by step methodical process and not to do something that may very well make the issue worse.
A couple other things you may try for a temporary work around;
Disable IPv6
Manually assign static values for the IPv4 addressing scheme.
Open task manager and under the processes tab look for mdnsresponder, if it's there then you may need to take steps to disable...