Installed programme

A program on the disc contain the executable code and a header file containing a list of all the resources required. When it is executed it firstly allocates resources to itself (RAM etc). Some of the code is not contained in the disk file. For example DLL's (Direct Link Libraries) may be stored separately and only linked onto the program.

Installing a program is actually just putting reference into the registry. This registry enable the execution of a program by selecting a file with a specific extension.

For example if you click onto a .doc file Word will be executed or activated.

The above may be a simplification of the protocols involved.

Exceptions are also the rule.

Hendrik,

I vote for this excellent answer.

An installed program usually is a fairly large program that is installed with installation software (a little redundant). Installed programs may change settings on your PC, including making changes in the Window's Registry Files.

An executable file can be a program that just has to be copied onto the disc to be run. It can either have an icon to click on (like an installed program) or not, but can be run by typing its name at a command prompt or in the run box. These files usually have a .exe extension, indicating it's an executable file.

Of course, most all "installed programs" are started by invoking a .exe file, as well -usually through clicking on an installed icon.

installed program is complete application program you install on OS .Further EXE , INI , DLL ,SYS,TXT ,BAK ,LOG are different files that solve the purpose for program to run and control and complete task they are part of a program or generated by OS during installation.