Ethernet Network Adapter issue

Good afternoon

Bit of a strange issue here.

Two identically built PC's, same parts, same OS, same software, working in the same office.

One of the two machines kept losing its network connection with an 'unplugged cable' message. Rebooting the machine would magic the connection back until it saw fit to kick the connection off again. Could be intermittant hardware issue, so the box was shifted for repair.

Power saving mode has been disabled. have tried ipconfig commands /release, /flushdns and /renew, also used 'netsh winsock reset' and rebooted. Also reinstalled the network cards driver, which would also restart the connection until such a time the system decided that the internet isn't worth it.

Second PC perfectly fine. Still going strong and flexing at network connections, so we know there's nothing wrong hardware wise with the second PC.

Fantastic.

HOWEVER. Second PC ran into some issues with software (ran out of hard drive space which conked Sage software...) For the sake of speed, a nuke was the option, so in the meantime, the first pc which was designated as problematic donated its hard drive complete with all the previous software intact.

Second PC suddenly starts having issues with the network connectivity and intermittantly drops out....

Obviously the installation is at fault here, definitively a software issue BUT... I cannot figure out what this issue may be...

The system has had Symantec Endpoint Protection removed even though every other machine on the network is fine with the software. There is no other security software running on the machine that could cause me any issues here.

General clean up duties have been performed but this problem persists...

Any help much appreciated.

Try installing another Network Adapter in the problematic computer. Disable the onboard one, use the newly-installed one. See if that fixes the problem.

My guess is that your onboard Network Adapter is bad.