I have a troubling situation at work. I work in an office where there are only 4 people who work the weekend. And we work 2 people per shift. The bottom line is that I think my COWORKER stole my thumb DRIVE. Is there a way to tell WHEN a thumb drive has been removed from a Windows 7 computer? If I can pin point the time, I will have a much better way go about questioning him. Thanks in advance.

P.S., if you're interested in the story WELL, I know for a fact that I left the thumb drive at work because I remembered leaving it after I left the office and was on the road. When I saw him the next day (and my suspicion lay with 1 guy) and asked him if he saw it, his responses were a joke. He was nervous and uncharacteristically squirrelly. I know this guy took it. I just need a little more proof. Anyone's help here WOULD be much appreciated.  I cannot help you with what you seek.However depending how important and secure you want the DATA on these devices to be (in the future) you might want to consider something like this:
http://www.truecrypt.org/
Then at least all you lose is a piece of hardware (unless of course your activities and those of your associates are linked to the NSA). truenorthThis utility: http://www.nirsoft.net/utils/usb_devices_view.html

It should list the date and time when unplugged under one of the columns. You have to know which device it is though. I have not used it on 7, but it should work.