>i try to use the following:-
>
>clear program
>clear events
>erase
>
>the same error message.
>
>clear all
>
>you can't use this command on running application.

The only other thing I can think of is perhaps, if you have just closed or exited the exe file, and then you immediately try to delete it, maybe the file system has not finished releasing any locks it might have on the exe file. You might be able to get around this by introducing a delay before you ERASE:

CLEAR EVENTS
CLEAR PROGRAM

=INKEY( 2 ) && Waits 2 seconds

ERASE ...