XP won't recognize USB Flash Drive

One of the guys I work with has a USB Flash Drive he would like to use at work. He’s used it successfully on the office computer before, but recently the computer hasn’t recognized the drive. It’s still the exact same computer with the exact same OS (Windows XP). But now when he plugs it in he isn’t able to access it at all because it doesn’t appear in Windows.

The drive is still recognized on his home computer, so it’s not that.

Any idea of what might have happened?

I don’t work with that computer at all because I don’t need it for my job, so I’m not sure if maybe someone changed a setting or what.

Thanks for any help!