I said on the home page to make sure you had Speccy or another internal system analysis program open while you browse this guide to get a ballpark figure of what your system can and can't do. If even the games in the High Performance category aren't working, then I think you should be spending a little less time here and a little more time finding out how to get the money you need to upgrade your system.
Google it. I'm not being condescending. For instance, it took me all of one google search to figure out why Space Hulk Ascension was giving me pink boxes for some particle effects; I simply had to update my drivers. What kind of sentence did I put in Google to get my fix? Space Hulk Ascension Pink Squares. If it isn't on the first page, try the second, and the third. Mix up your keywords a little.
Updating your drivers is solution number two to general graphics issue, since ATI/AMD and Nvidia put a lot of money into fixing their products despite scandals like WOOD SCREWS.
Visit /scurv/, since there should be some image guides there. Or Reddit, if you don't automatically know where /scurv/ is. "Front page of the internet" should have a little bit of everything; hell, someone would probably hold your hand through every step over there.
Some games just aren't on there because I compiled a quick list first and slapped HTML on it. I'll be updating this place for a good long while. I also don't know what your "shitty computer" entails.
Tech support isn't the purpose of this guide. Go use Logical Increments or something (if the new javascript abortion version of the site actually loads for you - it barely does for me).
Not usually, no. They're a placebo more than anything else. They're the kind of programs that make people create parody websites like downloadmoreram.com.
The free edition does exactly what you need it to do: tell you what components make up your computer.
If you're gonna interact in any way with things under the hood when it comes to a game, like making that .bat file for Diablo 1, I suggest using Notepad++ because it'll be a lot easier on your eyes even though you might never even think about programming, scripting, or HTML/CSS ever in your life.