Internet works but Desktop won't detect Ethernet Cable

Okay, so, I have a computer running on Windows 7 Ultimate, Dell computer.

My internet works fine.
But my computer doesn't detect my Ethernet cable, which causes some problems.

One of the main problems it causes that it causes some apps to crash on startup, or they work but will never fully load, making them completely inaccessible.

Is there a fix to this? If there is, it would be greatly appreciated.
Note- If this information helps, this problem happened straight after I reset my Desktop to a different point. The reason I did this was because my whole screen went black and all I could see was my mouse.