Check if a program exists before installing with Inno
To check if a program exists before installing with Inno add the following code section to the installer script. In this example we will be testing for the file “c:\Example\Test.exe”. If the test.exe file exist a message box showing “Program Already Exists” will be displayed and the installer will terminate.
[Code]
function IsMyProgramInstalled: boolean;
begin
result := FileExists('C:\Example\Test.exe');
end;
function InitializeSetup: boolean;
begin
result := not IsMyProgramInstalled;
if not result then
MsgBox('Program Already Exists', mbError, MB_OK);
end;
Download the installer script IsMyProgramInstalled.iss