Dell Latitude E5530 - Unknown Driver/Device Solution
If you wipe the OS and reinstall with lets say; Windows 7 Enterprise; then you will be missing a few drivers.
There was one device that just kept showing up as "Unknown Device" in Device Manager and turns out that it was the Hard Drive free fall sensor. If you go to support.dell.com you will find that under the driver downloads and then the chipset section.
The one I used was:
|Free Fall Data Protection|
|v4.10.0036 (A05) January 02, 2013|