EXE files open with
It looked like a severe XP problem: every application opened with my Notetab editor instead of being executed. When I moved to Notetab to another directory, the system asked me for the application to open EXE files with - which is paradox. They're executables.
What had happened?
I had mistakenly tried to open an exe file by right click and sent it to Notetab and left the mark at "always open with".
The registry got a new key in:
The was a new key for ".EXE" pointing to Notetab. When I deleted it (the whole .EXE path), the problem was solved. I didn't even have to restart the PC. Before that, it was necessary to rename regedit.exe into regedit.com (Windows directory) to access the registry editor.
By the way, a few applications did work from the start menu. Probably because they took the detour via a shortcut.
In other cases the problem lies in HKEY_CLASSES_ROOT at the .exe and exefile entries. Look up your favourite search engine for a file called exefix.reg, download and double click it and restart the PC.