Running a process as another user in ASP.NET

I have an ASP.NET MVC web application and in one of the controller actions I want to start a process (exe file). The process must run under a domain user because it accesses other resources in the domain. It can be either a single hard-coded user or a user who is currently on the web page. The web.config uses Windows Authentication.

I tried to enable impersonation and tried to turn impersonation when specifying a specific user. Both of these scenarios will cause permission issues.

I also tried to run the process as a specific domain / user / password, but that would give me the error "Login failed: unknown username or invalid password". I'm pretty sure the username / password is correct and the "runas" is working fine.

I'm not even sure about the correct way to do this. Any help is appreciated.

Thank.