how to detect is a application is already installed.

Archive: how to detect is a application is already installed.

Reeyasen
28th November 2001 05:32 UTC

how to detect is a application is already installed.
Hi Friends.
I want to know how to detect if an application is already installed. So that if it is installed, then NSI should not continue with installation.

regards,
reeya

F. Heidenreich
28th November 2001 09:42 UTC

Hi Reeya,

you could do this by checking an registry value that have to exist when the app is installed or by checking for the app.exe.


IfFileExists "app.exe" lblAppExists lblNoAppExists
   lblAppExists:
   MessageBox MB_OK "App already installed!"
   lblNoAppExists:
   SetOutPath "$INSTDIR"
   File "app.exe"

or by registry value:


ReadRegStr $0 HKCU "Software\YourName\YourApp\Settings\"  "Installed"
IfErrors lblNoApp lblAlreadyInstalled
   lblNoApp:
   SetOutPath "$INSTDIR"
   File "app.exe"
   lblAlreadyInstalled:
   MessageBox MB_OK "App already installed!"

You can use the Abort command to stop the installation process.

Hope it helps -
Regards,
~ Florian

Reeyasen
28th November 2001 11:09 UTC

Thanx
hey...

Thanx a lot. appreciate.
I actually got it working using similar procedure.

Thanx again.
Reeya