I would rather use a single vbscript to do the following tasks

- Prompt a dialog box to user whether to install or not
- If YES, Check for the existance of the application
- If the application doesn't exist then only install

To display message box to the user before install, try my script at

https://www-secure.symantec.com/community/download...

Let me know so that i can help you with the script.

Good luck

found this:

Prerequisites page. Additional runtimes have been added to the Runtime Details dialog. To access this dialog from the Prerequisites page, select Add > Runtime.

in here:
http://www.altiris.com/upload/wise_002.htm

as far as i understand, wise installer should handle Prerequisites in installation...

I assume you are compiling to EXE as this is the simplest way of distributing your MSI together with any pre-requisites. When you add a pre-req to your EXE project, you will find that the button that allows you access to the wisescript that forms the EXE "Wrapper" is enabled.
Once you get access to the Wisescript, you can then add additional code around the section that installs your pre-requisite, to perform any checks you require, prior to installation.

I think this is really a good method to do it.
You can create an external VBScript in which you can first call this and then your package.
Good script Eshwar

The simplest solution that does not require scripting is to use system search. If an application is already installed, it should have an entry in Add/Remove programs, so you can search for its registry footprint at
HKLM/Software/Microsoft/Windows/CurrentVersion/Uninstall/{product Code} - check for something like Display Name in the many keys that are present.

After packaging the application we always use VBscript to install the application [along with TRANSFORM if applicable]. There are advantages of installing an application using vbscript like...

- Checking prerequisites
- Returning exit codes to the ALTIRIS

We deliver the applications using ALTIRIS and it is always important to get an exit code returned to the ALTIRIS, informing whether the application has been installed or not.

For more information check the following:
https://www-secure.symantec.com/community/article/...

You can always display message boxes before and after installation using vbscript.

For more information check the following:
https://www-secure.symantec.com/community/download...

Yes, it is good commercial practice to have an established process for all apps. Out of interest, have you tried the vbscript solution on Vista?

We have Windows XP SP3 environment. I never worked on Vista as far as scripting is concerned.

If you have the opportunity to do some testing on Vista, then take it. Vista offers a lot more challenges to packagers due to the UAC - it can and does prevent wisescript and vbscript custom actions running and you have to pay a lot more attention to code signing, or turn off the UAC, which many corporate users will resist due to security issues.