How to check if another application is installed

[MikeFieger]

Hi!

I am currently writing the Installer for our program 'B' that is a kind of add-on to our program 'A'.

So I want to check if program 'A' is installed before installing 'B'.

How can I check this?
Program 'A' is not creating registry entries, but I know its Product-Code.
The installer for 'A' can hardly be enhanced to writing registry entries as it is already shipped to our customers.

I also would need to find out the $TARGETDIR$ of 'A' because 'B' has to be installed in the same dir without asking the user again.

Can this be accomplished?

[MichaelNesmith]

First is easy - use the Is MSI Setup Installed command. This works with the GUID that you already know, so its great way to do it.

Second - this will be trickier. You have to know some registry key, some product file, some way to track down a change made by the product. You can try Find All Files, Read Registry, etc. from that point onwards...

...but there's got to be a starting point!

[MikeFieger]

Thank you!