How a LocalSystem Service can run an application as a user [C#]?

Question

On my local machine I am running an administrative c# service as LocalSystem called Serv.exe which performs various tasks. One of the tasks it needs to perform is to launch an application under the USER account (currently logged on), not as admin - as this violates security.

The obvious solution would be simple impersonation when launching the application - however I run into a small problem whereas I am not priviledged to the user account credentials (Username & Password) and therefore am unable to impersonate in the conventional way.

So, using a C# service running as LocalSystem when logged on to a User account - is there anyway I can launch an application as that User?

From the comments:
what happens is that the Application itself asks the Service to do a job and then terminates. when the job is funished the application must restart itself - I thought the best way would be to have the service restart it when it was done ...

Any help would be greatly appreciated. Thanks,

Answer 1

Instead of breaching security this way you can make the application wait and then restart itself. See this SO question and this one.