Hi, erm, please just bear with me, as is this not only my first time attempting to download and use a mod, but I'm also on a brand new machine with Windows 8.1 and still trying to figure all of this out. I'm like, 99.99% sure the problem is me doing something wrong, I just have no idea where or what it is, so I'm going to be as detailed as I possibly can.
I have, installed and working, the complete games of both Morrowind and Oblivion installed from disks (but they do show up on my Steam account). I downloaded all the prerequisites that are listed: • Unofficial Oblivion Patch (and to be honest, I don't have the slightest clue where to place this), • Official Oblivion 12416 Patch (also don't know where to place this) [this is a presquisite to use the Unofficial Oblivion Patch], • Obse_0021's (placed in the Oblivion>Data), • Ely's Silent Voice (placed in Oblivion>OBSE>Plugin), • MenuQue Obse (Oblivion>Data).
After all of that, I have downloaded the Morroblivion v063a Master-file Installer and the Morroblivion v063 Complete Resources (also not sure if these need to be placed somewhere specific). This is where things and I definitely go wrong. On the detailed page, it instructs to "Unpack the .exe file from the archive and run it." My computer doesn't recognize this file and thus asks me what program to use (none are listed) and then brings me to the App store, in which I just downloaded a program called Unpacker. I have no idea if I'm suppose to be using a specific program or if it doesn't matter. After I open that program and unpack the .exe, I go to open it and an error pops up stating that "This file or directory is corrupted and unreadable."
Annnnd that's as far as I've gotten with this, because Google is currently failing me lol. Any more details and such would be a major help, because I know this works, it's just me doing something wrong, and I want to start playing this asap lol. Please and thank you!
EDIT: So I did some rummaging and discovered that 7zip is the program to use, so I have acquired that and tada! - the .exe works, so I go to hit install for that and then an error message pops up exclaiming: "You haven't got Morrowind GOTY in this directory!" So, I'm not sure exactly what that means, and how to go about fixing this.

Unofficial Oblivion Patch
It's installed like any other mod. I'm pretty sure there should be installation instructions on UOP's Nexus page somewhere.
Official patches come as exe installers IIRC.
No, OBSE goes into base Oblivion folder. It has installation instructions in the readme.
MenuQue goes in the same folder as USV.
This means pretty much exactly what it says - installer cannot find Morrowind files in directory you selected. Make sure you've specified the right directory - the one where Morrowind.exe is located.