Network Internet Stops Working after Flash HDD applied

[Guest]

Network Internet stopped working. Small business. They have a network of 5
computers. There may be a server of some sort. Tried to trouble shoot as
many ways known. The OS is Windows 2003 Server?! A system restore was not
found. All 5 computers cannot connect and the page cannot be displayed. A
customer inserted her own private flash drive into the USB port when all
Internet Connections shut down. Attempted resetting by powering off,
unplugging everything and reversing those steps. Used system restore on the
computer that had the personal flash drive inserted into and still not
working. Tried connecting to Internet from main computer in safe mode and
still Cannot Access the net. Did flash drive have a virus or can something
else be the problem due to flash drive being installed? Are there
troubleshooting steps to fix the problem?

 

[Dave B.]

A server of some sort? Server 2003 is definitely a server.
Is net access through the server or through a router? Does the router have
net access?
Is DHCP in use? Is the DHCP the server or the router? Is it working?

As you can see, allot more info is needed to help with the problem.