How to Reformat computer using a USB?

So, a couple of years ago, I did a clean install on my laptop (Windows 7 Home Premium/Sony Vaio), booting from a USB, and everything went well.

Now, I'm trying to figure out how to simply reformat it and do the same thing over again, to refresh. There's nothing tragically wrong with the laptop, it's just slow, freezes, and is generally chocked full of crap.

I'm wondering if I can just go ahead and do the reinstall windows recovery option, but instead of using discs (because my disc drive is broken), use the USB? Would that work instead?

I apologize if this question/complaint is trivial. I'm not terribly computer literate to the point of being confident that I won't screw everything up.

Yes, I was there and already copied that ISO.

My main question is, what method do I use to format the computer in order for this to work? When I did it before, I didn't have to worry about it because there was no OS already on there, it was just empty.

There isn't any reason to save any partitions so you can delete them all during the booted install and create and format New or just click Next to let the installer do it.