Hi, I'm using 2012 Express Edition, Version 18 SP1. I know this is old, but it fits my requirements.

I am having problems with the software requirements feature. I want to make sure that a particular version of my software is already present on a user's system before allowing the installation of an update to proceed.

In my installer for the update, I have tried to create a custom requirement using the 'Create New Launch Condition' feature. However whatever I do the condition is not satisfied. I have tried checking for the presence of a file with and without version and date limits. I have also tried checking for a registry key and that doesn't work either. The only time I got something to work was by checking for the presence of my main executable and that it had a date greater than a certain value. It did detect the file and allow the installation to proceed, however the installation failed as it said the executable was in use/locked for some reason and couldn't proceed. The executable wasn't running and wasn't in the task list.

Any ideas?

Many Thanks