Network / Sharing :: How To Share Files On Windows 8

I have been trouble sharing files with windows 8. I basically went into network & sharing center and turned all of the options to ON (or yes, whatever lol).

The machines are both running windows 8 on a wifi network.

I noticed a few things: If you right click the wireless network, you can "toggle" and turn on/off file sharing. This is a tad confusing, windows 7 never had this option. Also, do you need to be on a "homegroup" in order to share on windows 8?

There are a million variables!

Variable 1: Variable 1 is comprised of a million different variables and is the "network and sharing center". I Have all options set to "On", and still can't share.

Variable 2: Variable 2 is the right clicking on the WiFi network and clicking "turn network sharing on or off". Mine is set to off at the moment, but why is this separate from variable 1?

Variable 3: The final variable I can think of having a homegroup. I don't have a homegroup setup right now, do I need all machines to be on a homegroup to start file sharing between computers?

What I want: I want to be able to share entire computer contents between machines.

Back in the windows 7 days I used to be able to hit "run" and type in //computerame/c$ and I had complete file access to other computers on the network. How to accomplish that with Windows 8? That way I can access all files, not just "shares" on computers on the network.

PS: Right now, when I try to connect to other machines on the network, I get a username/password prompt. No matter what I input I get an error and it won't work.