Could you edit an executable file when it has been compiled? Yes, you could. But you could only change the String data. How? Using the MS-DOS Text Editor. The String data is text, but in the file will appear different. For example, if in the application appears
About NotePad in the compiled file will appear A b o u t N o t e P a d with an space between each word. Before modifying the file, make a back-up of it. If you want to modify the file, first you have to open it using the MS-DOS Text Editor and open the file as Binary. Then activate the Insert key and search for some text data in the program. But, it isn't as easy as said. You have to search it manually, 'coz the words are separated by a space between. Then replace each word for anyone you want. Example:
N o t e P a d to M y P r o g r
BE CAREFUL: The file must weight the same than the original; if not, it could not work.
[Even then the file may not work. For example, it might calculate its checksum and notice that you have made changes. This is certainly a dangerous technique. So at least make a backup copy of the file before you mess with it.
Any more doubts contact me.....