windows 7 OS network error

Wireless or Wired?

Dear paulmacd:
it shows yelllow mark on the network sign .and shows no internet access .
i have confirmed that there is no other machine with same ip address
yes address is valid on network

yes i tried different cable too
yes i tried difefrent port also

this problem is not certain as if i put pc on DHCP it works properly and once if i disable and enable network card it works for some time properly and gives the same yellow mark and shows no internet access .

j_meca:
its a network connection.

wired one

its happeneing with all windows 7 pc's when i freshly installed them . later they got corrected themselfs .
i dont understand what issue is this

Do they start out with valid Default Gateways?

sorry come again

"its happeneing with all windows 7 pc's when i freshly installed them . later they got corrected themselfs . i dont understand what issue is this "
My question is, what are the networking settings when you "fresly install" them?  I suspect the information is wrong and I'm wondering what settings you use.  What's the result of an IPCONFIG /ALL command on one of these machines?

For me, I often have to disable IPv6 and run a tool called 6to4 remover (http://www.ryanvictory.com/posts/automating-6to4-adapter-removal-in-windows/) to restore network access to some Windows 7 workstations and Windows Server 2008.  Our DC's are still running Windows Server 2003 so that was our reason on why these network settings have to be tweaked to keep it from going haywire.

when i run my windows 7 pc on dhcp iits working fine , but when i assign it a unique ip address it works for some time but later showing yellow exclamation mark with no internet access .
IPCONFIG also gives up same ip rage which i have assigned
kindly advice

When you assign an IP address, is it in the range of IP addresses your DHCP server hands out?  If so, it's likely there's another computer on the network with the same IP address.

no i have properly checked the ip addresses , and the pc does not hangs out, as it work for some time but later it shows no internet access and yellow mar comes

please advice

When the exclamation point appears, try pinging 127.0.0.1 and also try pinging the default gateway address.  Let us know what the results were and we may be able to advise further.

Another good test (when the error is present) would be to go to a different (call it "good") computer on the net and ping the IP address of the problem computer.  Then disconnect the network cable on the problem computer and ping it again (from the good computer).  Those results would be useful here.

It would  also be useful to see the exact results that ipconfig /all produces, as Paulmacd requested.

thanks

Thanks for the points, but can you tell us what you discovered?  What, if anything, resolved the problem?