Error 814 ?

I'm running Vista pro with a small home network. Now somehow last Friday my router failed to connect. Both my other pcs are connected directly, hard wired to the router.
If I connect only via the moded it works fine, but I have had the modem checked at work and it's working perfectly, even tried a brand new router which also failed, and tried changing the connection cables with no success.

Having googled, it suggested updating drivers, but this came back saying they were up to date. So I tried a system restore back a week which was earliest available, systems could not be fully restored and problem remains...Ran a thorough virus scan with avast to no avail....all out of ideas now....Anyone help ????

 

Not being a network expert, the only thing that got me once - is that the modem could not use the slot next to the slot used for the connection to the router. Try another slot. Also, try connecting just one at a time to see if it can connect to the internet.

 

OK I will repeat ..

I have a small network all wired directly via the router, 2 pc's & a laptop (2 x vista & 1 x XP) all was working fine until just over a week ago when the others lost the connection via the router. When I wire directly to the modem it still works fine (I'm using it at this moment). I have taken the router to my work and it again works perfectly. I have since changed the cables connection router to my network with no success. Have also checked for updated drivers with no success. I have also tried to connect with a brand new router (nephews) which also failed !!

Finally I tried to do system restore but for some reason, windows did not fully restore to previous dates. A virus check using avast has failed to find any problems.

I'm all out of ideas so pleased to listen / read any suggestions