UR22 input not possible

Hi …
Please pardon me if I’ve overlooked another thread.

I have this selfbuildt Windows 8.1(all updated) PC With an Intel i7, 18GB RAM and AMI 02.61(updated) connected to a Steinberg UR22
Up until today I have been able to Connect my guitar, and play along, but when I turned the computer on today, the USB LED lamp is on, but no red light for the peak.
When connecting my guitar, there is no sound coming from it. But the system sounds of my Windows is working fine.

What has happened?
Is there a solution to this?