Block Executable File With Password

LockAnEXE, a free, simple program lock, that lets you 'lock' down executable files and prevents them from being opened. Simply click 'Open File' and browse to the program EXE or the setup EXE. Click the option you prefer and click 'Do It' to lock or unlock the EXE.  It is simple, yet efficient exe lock.

Link: freeware to block executable file