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Since the issue happens after Windows update, you can look into loading restore point to bring your system back to previous state prior to the installation of windows update. System restore
can be found in Control Panel, Recovery -> Open System restore. Perfoming System restore will remove apps, drivers and updates installed after the restore point was made.
Another option is to uninstall the Windows updates. This can be found in Settings app, navigate to Update & security > Windows Update, select “Advanced options”, select “View your update history”, and then select “Uninstall updates".
Other troubleshooting steps you may consider:
1. Download Administrator tools for Intel(R) Network Adapter from this link:
-Extract the files and locate "Diags.exe"
-Copy the "Diags.exe" to your DOS USB key
-Boot up your system to DOS prompt
-Run the "Diags.exe" to check if the Intel(R) PRO/1000 PT Dual port Server adapter is being detected
2. If you have spare system, try installing the adapter on that system to isolate if problem is with the Dell system or adapter.
If the Intel(r) PRO/1000 PT Dual port Server Adapter comes pre-installed in your Dell system, suggest to contact Dell for similar issue encountered by other user and available fix.