AMD 970 chipset Gigibyte MB
Win 7 Pro
Realtek on-board chipset with a 1/18 dated driver update.
It's kinda hard to describe this,, but long story short;
I was tiring newer versions to update those bootable CD's with troubleshooting programs on them for possible future use (hopefully not) eg;
Ultimate Boot CD,
Knoppix v7.2 & 8.1
EaseUS Partition Master WinPE,
All IN One Rescue Toolkit,
MiniTool Partition Wizard
for examples.
I believe it was one of the Knoppix versions that did something as they have Ethernet drivers so one can use the included browser, but that is only a guess.
Somehow, the on -board Realtek Ethernet chipset got disabled or corrupted to a point I had to connection to the Router. The 1st time, in Device manager, the network device entry wasn't even there. I managed to get thing back, I believe by powering down and/or rebooting.
The 2nd time, Device manager had the Ethernet device entry there and it showed that it was working, but no connection. Network & Sharing showed a "Unknown Network". The Router showed the port connected as did the LED's on that back of the Tower including activity. I couldn't even access the Router.
I reset defaults in the UEFI BIOS, but that didn't work. Then I did something that I haven't had to for probably 16+ years, I cleared the CMOS on the MB, then reset the BIOS again on bootup. Connectivity was restored.
So, the question is; what could of been done and how did this happen? How could a program outside of the installed O/S affect a on-board device after the program is closed? Has anyone heard of something like this happening?
Mind you, I also didn't have connectivity when I re-loaded two of those bootable discs, so this is NOT a W7 O/S issue. I have a 2nd bootable HDD (same O/S) and that was dead also.
I don't believe it was a 'virus', the iso's that I burned to the CD's came from the original source.