The Code 28 error is one of several Device Manager error codes. It's caused by a missing driver for that particular piece of hardware.;
How to Fix a Code 28 Error:
Restart your computer if you haven't done so already.
There is always the slim chance that the Code 28 error you're seeing in Device Manager was caused by a fluke with Device Manager or in your BIOS. If that's the case, a reboot might fix the Code 28.
Did you install a device or make a change in Device Manager just before you noticed the Code 28? If so, it's very possible that the change you made caused the Code 28 error.
Undo the change, restart your PC, and then check again for the Code 28 error.
Depending on the changes you made, some solutions might include...