Ok, I am so stumped and hope someone can help. I am Technology Director for a public school system. All of our vista machines began randomly disconnecting from the internet this week. Local network connection is fine but can't connect to the internet. We believe it has something to do with the fact that one of our domain controllers crashed and was removed earlier this week. When the disconnect happens you can disable/enable the connection and it will connect again only to disconnect in a matter of minutes. This happens with wired or wireless. Now here is the wierd thing, if we assign a static ip in our 172 ip range (which is the range of ips in our DHCP server) same problem but if we assign an ip in the 192 range no problem, it stays connected all day. I don't know if this is a related issue or not but I also noticed that occasionally after disable/enable is performed, the local connection and the wireless connections are both named network 4. I noticed this on two of our vista machines at the same time and another time it would read the local connection as the wireless connection (Crazy I know). Our networking administrator worked on this all morning and thought he stumble on a solution. He found traces of the crashed server and deleted them (I think in active directory). It seemed to have fixed it at first. I was able to stay connected for about 2 hours but before the leaving work for the day it began again. I have no problems at home and none of our xp machines are experiencing problems. I also remove myself from the domain and renamed my computer, same problem. Flushed DNS no fix. During the disconnected times We can ping all of inside server but can not ping outside. I feel certian that it has something to do with our now missing server but I don't know enough about the server end of networking to figure it out and quit frankly I believe this is the wierdest thing I have ever had to trouble shoot. Any help or Ideas would be appreciated.