First off, can you update your system specs with all available info, please? This will go a long way to helping us help you.
System Specs - Fill in at Ten Forums
Second, have you tried updating the drivers for your ethernet hardware?
IMHO, this sounds like a hardware issue. Of course, try updating the drivers first, this may help fix the issue.
Other things that may help is taking care of any system file corruption.
Start off by opening a admin command prompt and typing: sfc /scannow. If you have system files that are corrupted, this should fix it.
After that, type: dism /online /cleanup-image /restorehealth. This will fix any component store corruption.
Then, type: chkdsk C: /scan. If this comes up with errors, type: chkdsk C: /F /R. IT will ask to schedule the scan for the next restart. Say yes, then restart and let it do the scan.
There are a multitude of issues that can be fixed by these three simple steps.
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