Windows 10: i can't shared my printer in 1 pc to another pc that connect to same modem with ethernet cable

i can't shared my printer in 1 pc to another pc that connect to same modem with ethernet cable

:)

 

Unable to connect to Cable Modem


I have an issue with my Windows 10 PC not connecting to my cable modem by ethernet cable. I connect the PC to the modem and all I get is "unidentified network - no internet", yet my laptop connects to the modem by ethernet (I'm using it now) just fine. I've tried everything I can think of to get my PC to connect to the modem, but nothing has fixed the problem so far. I can connect my phone to the modem fine by wifi as well, so the modem isn't the issue - or is it? Yesterday I had no issues with connecting to the modem and internet until I had a "blue screen event" and when the computer rebooted, I had the yellow triangle ! ever since.

Please HELP!!

 

Weird issue with cable modem, speed, and connection

I have an Arris cable modem from Spectrum. It has 4 ethernet out ports. For many months i've been running two ethernet cables out from it, 1 directly to my PC 3 feet away, and one to the router for the rest of the house.
reason: if i go to the router, then out from that to my PC, i get about 65 Mbps. If I ran direct from the modem to my PC, I always speedtest at my full 120 Mbps. I gave up trying to figure out why my router was only yielding roughly half speed, and since a direct ethernet from modem worked, i left it at that.
This morning upon turning on the PC, i had no internet on my PC. I checked, and the rest of the house is fine. Now, no matter what, I can't get internet to the PC on the direct line from the modem. If I run a line from the router to the PC, it works, but still at ~50% speed
I have tried:

• all network reset commands (netsh winsock reset, etc)
• rebooting PC
• rebooting modem (twice)
• windows updates, incl drivers
• running network troubleshooter
• running ONLY direct line from modem to PC (pulled line from modem going to router)
• switched ethernet wires
• using 2nd ethernet in port on PC

by the way, months back, in trying to solve the 50% speed problem, I went out and bought a new router with all the latest standards, and to my amazement, still got 50% speed. So yeah, I have no idea what's going on.

 

Windows detects no ethernet cable is plugged when connected directly to modem

I had a network setup which consisted of a modem and a
Wifi router, where the router is connected to the modem, and all other device is connected to the router.

Recently my ISP offered to change the old modem to a newer modem+Wifi router combo, which had better performance than my old standalone router.
When migrating, every device connects to the modem properly, except for my PC, which detects no ethernet cable is plugged when it was connected directly to the modem. Sometime it got network access, but that only last about 10 seconds before windows said the cable is "unplugged" again.
On the modem side, the ethernet port was blinking green every one seconds. Sometimes it goes orange, but most of the time. It just stay blinking green.

I tried conneting the pc through the router then the modem and the PC connects to it fine. But that setup takes a lot of my space, not to mention the router is ancient.
I also tried reinstalling the driver using my MoBo included driver disk, but to no avail

Thanks in advance!