USB Mass Storage Device Will Not Recognize External Storage Devices?

Keyboard and mouse drivers unaffected.USB Mass storage device properties messagewith driver check on:"Windows cannot verify the digital signature for the drivers required for this device."with driver check off:Tells me drivers are corrupt or missing.Search show diver where it should be:C:\Windows\System32\drivers\usbstor.sys (also usbfilter.sys).Used the HP Recovery Manager to restore factory setting for USBStor.sys, it indicates it is successful but no changeon reboot, still cannot use flash drives, SD cards, external HDs. Units work find on my laptop.Called HP 4 times, after extensive troubleshooting each time, following their instructions, go to hp.com/go/instant, get screen saying request has been received. Each time tech tells me he cannot find my request.After a while, read 2 hours, told they need to talk to supervisor, will call me back, KISS OF DEATH, never hear from them.