how to check if the application is running for the first time after being installed.

Hi,

There are different ways you can do it,

When your application runs, you can look up for a specific registry key ( keep key name such as it stays unique). If the key is not found then your application is running for the first time. Do the things you want to do for the first run and create above key in registry. So in next run, you will find the key and take action accordingly.

Also you may create a flag either in a database table or as a text file in your bin folder when your application runs for the first time.
On each run you can check for the flag and if not found then it is first run and then create the flag and if flag already exists then simply take action accordingly.

Hope this gives you some idea about your requirement.