Symptoms
Mouse and Keyboard keep connecting and disconnecting in a Windows Virtual Machine in Parallels Desktop 9. This action is followed by respective sound of a device connected to Windows.
Solution
Please update Parallels Desktop 9 for Mac by clicking on Parallels Desktop menu -> Check for Updates... and install the update.
Note: if you previously used this article to workaround the USB issue:
- Go to Virtual Machine menu ► Configure... ► Hardware► Boot Order
Remove this Boot Flag from Boot Flags field:
devices.usb.ehc=0