Windows 7 - Computer shows drive which isn't there

I had a friend who plugged his USB hard drive into my computer the other day and my computer wasn't able to use it (I think it was a mac format), but it still showed up in my Computer folder. When we took it back out, the drive is still in my Computer folder. It's been over 24 hours and I've restarted my computer... the stupid non-existent hard drive is still in my Computer. Does anyone know how to get rid of this? It's listed under "Hard Disk Drives" not "Devices with Removable Storage", so there is no eject option when I right-click.

Do you have a program (such as smartdefrag) that was mapped to this drive?

I have VirtualCloneDrive mapped to another drive (drive F), which works just fine. But this drive is mapped to drive Q, and it just appeared when I plugged the external hard drive in

Something to do with Office 2010 perhaps.

Probably. May want to see Office 2010 Drive Q for more information.

Also Office 2010 Starter Virtual Q: drive may intermittently disappear from My Computer and An overview of Microsoft Office Click-to-Run for Office 2010 are good further reading.

Hmmmm
However, his drive seems to have a bar under it showing how much data is stored. Mine is just blank.
Here's the message I get when I double-click it.

That is actually pretty standard. It looks like the image by Derekimo was of the Q drive he created to test if the installation could finish. See Extra Drives showing up in explorer, Mystery Drive (Q:), and Office 2010 Beta Click-to-Run causes Q Drive issue! - Microsoft Help | DSLReports Forums as they have the same behavior as your Q drive.

Wow, well I guess that must be it then - weird that it first appeared when I plugged in an improperly formatted hard drive

So do you know how to get rid of that Q drive? I don't see the solution in any of the links

Thanks

You would have to uninstall Office and re-install it without the Click to Run feature.