New Win 7 install on machine with Vista - clean install

Dell 1525 Inspiron
It's asking where do you want to install.

Disk 0 Part 1 OEM (Reserved)
Disk 0 Part 2 Recovery Primary
Disk 0 Part 3 OS System
Disk 0 Part 4 Mediadirect Logical

What do I want to "Delete" or "Format"?

Don't want to dual boot, don't care about mediadirect

Just want clean hd with only Win 7 on it..