Matt Neerincx
The key one is "The SQLBrowser service port is unavailable for listening, or invalid.".
So what happens is SQL Browser starts up and enumerates all network interfaces and attempts to bind to UDP port 1434 on each one found. If it cannot bind to any of the network interfaces, you will get the above error.
So run this from a command prompt first to locate the process id bound to UDP 1434 ->
netstat -aon -p UDP
Look for things bound to 1434, like for example PID 4736 below:
Proto Local Address Foreign Address State PID
UDP 0.0.0.0:445 *:* 4
UDP 0.0.0.0:500 *:* 1156
UDP 0.0.0.0:1025 *:* 1792
UDP 0.0.0.0:1026 *:* 1792
UDP 0.0.0.0:1027 *:* 1792
UDP 0.0.0.0:1434 *:* 4736
...
Next look up the PID in Task Manager to see what process this is. If it's a SQL Server process try shutting down all SQL Server instances and then restart SQL Browser. If it is some other process let me know what it is.
It is also possible that SQLBrowser did not find any network interfaces to bind to, for example if the computer has no NICs. Let me know if this is a NIC-less PC.