ElQuia wrote:Forget it. On starting XP VM I get the error as shown in attachements (screen capture 1 & 2). At the moment my usb web cam was active and I had a kingston pen drive inserted- With out ANY usb device = same error. VBox version is 4.1.2
As I said in my prev post, you need to install the test build I posted here (that hang the host for you).
You only need to remove or disable all usb device filters as Perryg mentioned, (you mentioned you have "an empty filter (a.k.a. "New Filter 1") and my web cam, "USB20 CAmera [0100]" - uncheck them or better remove).
Once you have no filters defined, you will be able to start a VM and it should not hang your system as it did before. Once a VM is started, please try dynamically attaching USB devices to a VM by right-clicking the "USB" icon in the bottom right part of a VM window while VM is running and selecting the device.
Dynamically attaching USB devices one by one should reveal which device causes the system hang.