It's a very basic I know, but have you checked if DHCP is on in the router and if it is, that the IP address you are allocating to the WIN 7 PC isn't already allocated to another machine?
You could also try allocating a static lease in the router for the WIN 7 PC, then if the addressing on the PC is set to automatic the router will allocate the address you want in any case.
You could also enter the static DNS server addresses into the router, that way they are also automatically allocated even if WIN 7 PC is set to autoconfig, but they will also be allocated to any other machine that connects using DHCP.
Yes DHCP is on, the IP pool was set in the router to 10.0.0.4 - 10.0.0.20 and the static IP is 10.0.0.3, which I know is not being used by any other device. I've now changed the IP range to 10.0.0.3 - 10.0.0.20 and in the tabbed section called 'Static DHCP' In 'Home Networking' I've now added a new static lease for 10.0.0.3 with the Mac address of the Win7 PC and set to Active.
The google and opendns ips were already set in the DNS section, however I noticed there was also a place to set static dns server IPs under the 'LAN Setup' tab (where the IP pool is defined) so I've also added those dns server IPs there too.
If you set up a reservation on your DHCP server you can essentially set a static IP address and leave the machine set to DHCP. The way it works is that you set it up by the machine's MAC address and when that MAC address requests an IP address it is always given the same address.
Yes, now done.
Is this the screen where you are attempting to save your "static" internal/local IP Address? FYI, typically the phrase "IP Address" refers to your "outside" or "outward facing" IP Address. Usually when reading things online the local IP's are called "local" or "internal". I just want to make certain you aren't trying to set your computer's local IP at your router, or whatever.
It's possible the information isn't being saved because it will not allow you to have to different DNS servers at the same time. My point is that there may be a flaw in the data you are attempting to save, so it isn't being saved. Also, if there is an internal IP Address conflict, example another device is trying to use the same IP, this might cause the problem. Finally, if your IP is outside the range, the data may not stick. Example what if your DHCP server's (router, cable modem or whatever) local IP range is outside the one you are trying to make static.
Yes that was the screen I was entering details, it was the local IP. This screen and the advanced section indicate that it should accept two dns server ips. There's no IP conflict between device boxes but there has in the past been a conflict between two network adaptors on the same PC, but I thought I'd made the system forget the extra NA. The static IP was outside the DHCP pool, however I've now included it and setup a static lease for 365 days.
Thank you all for your guidance. Sounds like in the past some interaction between router DHCP and PC networking has caused settings to dynamically change. Now I've setup a static lease on the router, I'll reboot the router and see how it works.