Until today I've been able to connect to the Internet through my Router using the Automatic IP etc. If I ran ipconfig it returned various connections similar to IP 192.168.0.2 Submask 255.255.255.0 Gateway 192.168.0.1.

However I cannot now do this and ipconfig returns IP 169.254.24.140 Sumask 255.255.0.0 and no Gateway.

If I change the settings in TCP/IP to manual and enter the correct IP as 192.168.0.x etc and enter the DNS as 208.67.222.222 (OpenDNS) then I can connect normally but receive a stern warning in having multiple Gateways. I have entered manual settings for the other laptops on my router and they work. But I have a VoIP Network Adaptor (Tesco) and that simply refuses to work and returns 0.0.0.0 for IP, Submask and Gateway.

Ideally I would like to return to the previous position of having all IP addressing Automatically set but I can't understand why I appear to now have a local network when I had a public network before. I have File & Printer sharing OFF. My settings in Vista are for Network Discovery to be also OFF.

Any suggestions on how I return to my previous working network configuration?

Are you connecting the PC to the router by ethernet cable or "wirelessly"? If "wirelessly", try using a wired connection and see if that gets its addresses automatically.

As the PC is getting a "169.254" address, the DHCP Client service is almost certainly running, but you can check to be sure. Go to "Start > Run", type services.msc and click OK. Double click the DHCP Client service to open its Properties sheet and ensure that the service is "Started" and that its Startup Type is "Automatic".

There is always the possibility that the problem is with the router, so go into its settings and check that it is still configured to assign addresses by DHCP. It might even help to "hard reset" the router back to factory default settings and then set it up again from scratch.

Many thanks. DHCP was indeed running on my computer but it was turned off on my router. So I restarted the router DHCP and I've been able to start using Automatic IP addressing via TCP/IP. The only outstanding problem is my VoIP Adaptor which is still having problems but that can be left for tomorrow!

For completeness - my VoIP Adaptor also had changed to DHCP OFF. When this was toggled to DHCP ON the Adaptor worked immediately. No obvious reason was found for DHCP to be OFF (on the Router and VoIP Adaptor) when they had apparently been ON for many months before.

Weird indeed. Glad you've got it sorted though.