Installing new hard drive?

Guys my hard drive went bad so I bought a new one and installed it. Now I need to install a OS on it. Problem is my cd drive is broke so I need to download a OS iso and put it on a usb key. I wonder if I need to go in to the bios to set it to load to the usb first, or will it automatically try to install from the usb.
BTW, I have the restore discs from my previous hard drive that went bad, but I am pretty sure I cannot use it to install the OS.
Win 7 is what I need to install.
Answer #1
You have 2 options..Either set the USB in the bios as the first device or use the boot menu..
Normally when you boot your system it says something like press Delete to go into the bios or F12 to for Boot menu..
You can check out your system instruction guide for the boot menu key..
Answer #2
Thanks. BTW, do I need to download anything for the usb to make it bootable or just put the iso on it.
Answer #3
You need the usb tool..It used to be supplied by Microsoft..Not Sure they still do…Google it..
Answer #4
It’s at:
https://wudt.codeplex.com/
Not sure why MS moved it off their site to have it hosted here; but anyhow …
Answer #5
You can try YUMI multiboot usb creator. You can add Windows 8.1 Windows 7 Ubuntu etc into 1 bootable usb.
http://www.pendrivelinux.com/yumi-multiboot-usb-creator/