I have a windows server 2003R2. It serves about 10 computers in our office via a gigabyte switch.

One time, several months ago, windows updated itself. WHen We came in on monday, nobody could log in. I checked the server and it kept alternating between "A Network cable is unplugged" and "Network Connection" . On Off On Off it would blink back and forth.

Our network guy said that windows updates can goof things up like that sometimes, so we should reboot the whole system manually. SO we shut everything down, including the firewall, cable modem, and switch. WHen it came back up, it worked again.

Now here we are 6 months later, and we are getting the same issue. This time, the reboot method didn't make it work. I was at the end of my rope when suddnely it held it's connection again. All by itself it decided to stay connected.

I do think windows update was involved this time as well. EVery time it decides to freak out, we lose lots of work. Has anyone seen this issue?

You said you think it's windows update, but do you have any evidence windows did an update?

You should be careful with automatic updates on a server, only security updates if anything, and doing all updates manually isn't a bad idea if you're able to pay close enough attention.

Are you sure this is the system itself? Problems with a router or cabling could cause the same problem and reconfiguring/adjusting the equipment could have fixed it.

Have you tried:

- Different cable
- Different port on the switch
- Different NIC
- Making sure your IP settings are what you expect
- Making sure no devices have conflicting IP addresses

Do you have DHCP setup on this server? Is the IP of the server static?

OK, I put aside my pre-concieved notion of Updates causing the problem and started trying different hardware checks. It turned out to be the LINKSYS switch. So I forced it to run at 100Mbps instead of the 1G, and it worked, the the slowdown was horrible. So I bought a replacement switch and everything is better now.

Thanks for all the input. It helped me step back and look broader.

Congratulations!