Local disk suddenly appeared?

I restarted my laptop yesterday, and when windows was booting, a brief error message popped up and said something about something being unclean... The message disappeared before I had a chance to actually read it, and then the computer booted normally. Now though, a local disk E has suddenly appeared in my hard drives. It was never there before, and I'm wondering if my computer has malware or a virus even though I have updated anti-virus software? Is it something to worry about or something I need to have fixed?