Well, this is definitely a problem of Apple. When iTunes use libtidy.dll and installs with their own version of this DLL compiled by Apple using the sources from the open source HTML Tidy project, it should load the DLL from its own program directory and do not require that Windows searches in all directories set in environment variable PATH.
Edward Mendelson1 has explained everything about UltraEdit perfect in his second post. Using the Express UltraEdit installation the program directory of UltraEdit is appended to the PATH variable. But when running a customized installation, the user can uncheck the option to add the UE program directory to the PATH. All options checked/unchecked during a customized installation are remembered and re-applied on next customized installation. I always install all applications using the customized option (if there is one) and therefore use UltraEdit since v8.20 without having its program directory in the environment variable PATH.
UE program directory in PATH is only required for the notepad replacement tool not available anymore (especially not for Windows Vista and Windows 7) and for those users which call uedit32 often from command line which do not want to enter always the entire path.
I personally keep my PATH variable free from any non Windows path, except of one special directory containing my own batch files and small command line utilities. But I use also some applications which require that their program directory is in the path. I start such applications not directly. I start each of those applications with a shortcut to a batch file containing in the first line
set PATH=Path(s) required by the application;%PATH%
and the second line is the application to start. So by calling this batch file, the application is started and has now the required directories in the local PATH used for searching for files without path and all other applications still use the minimal Windows common PATH.