Not recognizing device

I have a Blackberry Playbook that a computer does not recognize it. I can find it on another pc that is almost identical to the one that does not recognize the device. This is connected via USB.

Several solutions are offered here. Please ignore if you have tried them already:

Playbook not recognised on laptop via usb cable - BlackBerry Support Community Forums

Thanks!! Followed "uninstall adapter" and "wi fi off" and everything now works!!!!

Glad you got it working and thanks much for the acknowledgement too!