how to detect is a application is already installed.

[Reeyasen]

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]

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.

code:


IfFileExists "app.exe" lblAppExists lblNoAppExists

   lblAppExists:

   MessageBox MB_OK "App already installed!"

   lblNoAppExists:

   SetOutPath "$INSTDIR"

   File "app.exe"

or by registry value:

code:


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]

hey...

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

Thanx again.
Reeya