On Fri, 6 Apr 2018 19:56:19 -0700, OGER wrote:

Is there a simple, free way to detect if a CAT5 cable has an active
internet.

No. Nothing is simple.

The problem is that the two desktops running Windows 7 PRO do not show a
direct CAT5 connection, they just show a WiFi connection. Plugging in
the CAT5 cable does nothing.

That's correct. Plugging just a CAT5 cable, with nothing connected to
the other end, will not produce any form of connection indication. The
cable needs to be terminated by the LAN jacks on your AT&T FIOS
router. The AT&T router needs to be turned on and operating. You
should also see the lights on the ethernet jacks at both ends light up
when the cable is plugged in.

Once you get lights on the connectors, dive into Windoze 7 and see if
it recognizes the ethernet connection. Make life easy for yourself
and temporarily disable the wireless interface on the computah. Make
sure that the ethernet interface is enabled.

Start - All Programs - Accessories
Right click on "Command Prompt" and select "Run as Administrator"

Get a list of interface numbers, run:
WMIC NIC GET NAME, INDEX
On my Win 7 machine, my ethernet interface = 7 and my wireless = 12.
Yours will be different. No need to type the command in caps. Lower
case will work.

To disable the ethernet interface, run:
WMIC PATH WIN32_NETWORKADAPTER WHERE INDEX=7 CALL DISABLE

To enable the ethernet interface, run:
WMIC PATH WIN32_NETWORKADAPTER WHERE INDEX=7 CALL ENABLE

You should be able to see the effects of enable/disable with:
IPCONFIG /ALL | MORE

If everything appears to be working, try to ping your router. The IP
address of the router will be:
IPCONFIG /ALL | find /I "Default Gateway"
Then run:
PING IP_ADDRESS_OF_DEFAULT_GATEWAY
If you get a return, your computah can talk to the gateway.

If that works, the rest will be determining why your AT&T FIOS gateway
isn't talking to the internet.

Either something killed the desktops ability to access the CAT5
connections or the CAT5 cable is dead.

Or, the CAT5 cable is miswired or a crossover cable. Or, there's a
box between the computers and the router that you neglected to
mention. If it's a home made cable, I would be rather suspicious of
the cable.

It is an AT&T FIOS WiFi router.

Model number?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558