Posted 25 December 2011 - 07:36 PM
I dislike necro'ing threads, but I hate to think of other people having a similar issue, being told to get a new motherboard, and then do it when this can be fixed. I don't think the OP's issue had so much to do with the Arcsoft software, considering my issue did not.
My Vaio webcam stopped working out of the blue. I noticed this because I could not gchat on video. Thinking it was a Gchat issue, I uninstalled an reinstalled flash, java, and gtalk plugin. Nothing worked. Checked Arcsoft--didn't detect my camera. Device manager? Not listed. Device manager DID list an unknown USB though, much like the OP. Tried everything I could rationally think of--drivers, etc. Then my husband suggested the most ridiculous thing ever:
Shut the computer off (not restart). Unplug your power cord while the computer is off. Plug the power cord back in. Turn on your computer.
And it worked. No idea why, but it worked. My husband said that he's only had this happen since coming to the UK (we're expatriated here for a few years); please note that he has an American computer and I have a 'UK' Vaio as well, so I don't think it depends on that.
Good luck any future Vaio users who have this issue!