Hello World!
I'm a total beginner and had an absolute nightmare trying to get Code Blocks to find and use a compiler. The information on the internet is rather inpenetrable and isn't always correct. It took a frustrating and disheartening effort to solve, at least enough for a beginner.
However, I solved my problem enough to practice coding!!
This is what I did.
I reinstalled Code Blocks into my C: drive (it was in D: previously, though I don't know if that made any difference or not)
I then went here:
https://sourceforge.net/projects/tdm-gcc/?source=typ_redirectand downloaded TDM-GCC MinGW Compiler in the C: drive.
I then reloaded Code Blocks, settings >> compiler >> global compiler settings >> Tool Chain Executables Tab (to check the fields). The compiler was selected as GNU GCC Compiler. I then clicked "auto detect".
It FINALLY found the compiler.
This is what worked for me after hours of fruitless searching and inpenetrable reading. The key I think in my case, was the TDM-GCC MinGW Compiler download. Now, I don't know if this is the real, useful deep way to begin a multimillion dollar systems development lifecycle, but it will do for practicing beginner code.
Perhaps looking at the tool chain executables may have been redundant, but I just said what I did.
I hope this may help any who remain frustrated.