Configuring 8 gig as extra or ?

I bought external 8gig hardrive. I sent and copied programs and files to it. The problem is that when I try to open them up on the e:drive they wont open. They will on c: I have A: C: D:
abd now a E: What am I doing wrong? What did I do wrong. MY COMPUTER shows an E: Do I need to reconfigure master slave in my laptop or WHAT?