- Uninstall of Code::Blocks apparently doesn't clean up enough - the new install to D: pointed to a non-existant directory on c: that USED to be the location of the compiler. - I don't believe I missed a step about erasing things when uninstalling, as I was wanting to "start fresh".
There is no modern software that cleans the user files (config) when the software is uninstalled.
You have to delete the config files manually.
They are in ~/.codeblocks or %APPDATA%/codeblocks, depending on the OS.