USB not recognised by host

[Markjt]

I am running VB 4.3.16 on a Windows 8.1 64b host. Mostly it runs OK, but sometimes I have a problem with USB. Not on the guest but on the host. Sometimes when running a VM the host does not recognise any USBs I plug in, it just ignores them. I have tried many devices and unplugging re-plugging and nothing helps except rebooting the host. Then it all works fine. Anyone have any ideas?

[mpack]

It could be a lot of things: heavy CPU load, poor quality connector on the device, worn socket on the PC.

VirtualBox doesn't kick in until after the USB device has been recognized by the host lowest levels, so I don't see how your problem could be a VirtualBox matter.

[Martin]

Did you check that the running VM doesn't have an active empty USB filter which "catches" all newly plugged in USB devices?

[scottgus1]

I don't almost ever use USB in my guests, but I do have a Lenovo laptop running Windows 7 that occasionally won't recognize inserted USB mice or thumbdrives, and a reboot fixes the problem. Probably similar issue in your PC, Markjt. Host drivers, perhaps?