Non-existent Disk Drive

So I reinstalled my copy of Windows 7 a couple months back cause it was getting cluttered w/ crap that I wasn't comfortable with. That includes the Removable Disk drive E: that one day decided to place itself on "My Computer". I have no idea what the hell it is or why it's there. I'm extremely pissed because recently i plugged in a jump drive that i shuttle between here and school and discovered 6 high-risk viruses on it...   [wayyyy to go on keeping our school's network protected... dumbass IT guys that our broke school clearly don't pay enough] Norton removed them but I can't help to think (maybe it's in my head) that my comp is getting touchier and slower. So where did this drive E: come from and why cant i "remove" this non existent peripheral. Should I be worried?