Run PowerShell-Script from C# Application

Have you tried Set-ExecutionPolicy Unrestricted

using ( new Impersonator( "myUsername", "myDomainname", "myPassword" ) ) {     using (RunspaceInvoke invoker = new RunspaceInvoke())     {         invoker.Invoke("Set-ExecutionPolicy Unrestricted");     } } 

Edit:

Found this little gem... http://www.codeproject.com/Articles/10090/A-small-C-Class-for-impersonating-a-User

namespace Tools{    #region Using directives.    // ----------------------------------------------------------------------    using System;    using System.Security.Principal;    using System.Runtime.InteropServices;    using System.ComponentModel;    // ----------------------------------------------------------------------    #endregion    /////////////////////////////////////////////////////////////////////////    /// <summary>    /// Impersonation of a user. Allows to execute code under another    /// user context.    /// Please note that the account that instantiates the Impersonator class    /// needs to have the 'Act as part of operating system' privilege set.    /// </summary>    /// <remarks>       /// This class is based on the information in the Microsoft knowledge base    /// article http://support.microsoft.com/default.aspx?scid=kb;en-us;Q306158    ///     /// Encapsulate an instance into a using-directive like e.g.:    ///     ///     ...    ///     using ( new Impersonator( "myUsername", "myDomainname", "myPassword" ) )    ///     {    ///         ...    ///         [code that executes under the new context]    ///         ...    ///     }    ///     ...    ///     /// Please contact the author Uwe Keim (mailto:uwe.keim@zeta-software.de)    /// for questions regarding this class.    /// </remarks>    public class Impersonator :        IDisposable    {        #region Public methods.        // ------------------------------------------------------------------        /// <summary>        /// Constructor. Starts the impersonation with the given credentials.        /// Please note that the account that instantiates the Impersonator class        /// needs to have the 'Act as part of operating system' privilege set.        /// </summary>        /// <param name="userName">The name of the user to act as.</param>        /// <param name="domainName">The domain name of the user to act as.</param>        /// <param name="password">The password of the user to act as.</param>        public Impersonator(            string userName,            string domainName,            string password )        {            ImpersonateValidUser( userName, domainName, password );        }        // ------------------------------------------------------------------        #endregion        #region IDisposable member.        // ------------------------------------------------------------------        public void Dispose()        {            UndoImpersonation();        }        // ------------------------------------------------------------------        #endregion        #region P/Invoke.        // ------------------------------------------------------------------        [DllImport("advapi32.dll", SetLastError=true)]        private static extern int LogonUser(            string lpszUserName,            string lpszDomain,            string lpszPassword,            int dwLogonType,            int dwLogonProvider,            ref IntPtr phToken);        [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)]        private static extern int DuplicateToken(            IntPtr hToken,            int impersonationLevel,            ref IntPtr hNewToken);        [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)]        private static extern bool RevertToSelf();        [DllImport("kernel32.dll", CharSet=CharSet.Auto)]        private static extern  bool CloseHandle(            IntPtr handle);        private const int LOGON32_LOGON_INTERACTIVE = 2;        private const int LOGON32_PROVIDER_DEFAULT = 0;        // ------------------------------------------------------------------        #endregion        #region Private member.        // ------------------------------------------------------------------        /// <summary>        /// Does the actual impersonation.        /// </summary>        /// <param name="userName">The name of the user to act as.</param>        /// <param name="domainName">The domain name of the user to act as.</param>        /// <param name="password">The password of the user to act as.</param>        private void ImpersonateValidUser(            string userName,             string domain,             string password )        {            WindowsIdentity tempWindowsIdentity = null;            IntPtr token = IntPtr.Zero;            IntPtr tokenDuplicate = IntPtr.Zero;            try            {                if ( RevertToSelf() )                {                    if ( LogonUser(                        userName,                         domain,                         password,                         LOGON32_LOGON_INTERACTIVE,                        LOGON32_PROVIDER_DEFAULT,                         ref token ) != 0 )                    {                        if ( DuplicateToken( token, 2, ref tokenDuplicate ) != 0 )                        {                            tempWindowsIdentity = new WindowsIdentity( tokenDuplicate );                            impersonationContext = tempWindowsIdentity.Impersonate();                        }                        else                        {                            throw new Win32Exception( Marshal.GetLastWin32Error() );                        }                    }                    else                    {                        throw new Win32Exception( Marshal.GetLastWin32Error() );                    }                }                else                {                    throw new Win32Exception( Marshal.GetLastWin32Error() );                }            }            finally            {                if ( token!= IntPtr.Zero )                {                    CloseHandle( token );                }                if ( tokenDuplicate!=IntPtr.Zero )                {                    CloseHandle( tokenDuplicate );                }            }        }        /// <summary>        /// Reverts the impersonation.        /// </summary>        private void UndoImpersonation()        {            if ( impersonationContext!=null )            {                impersonationContext.Undo();            }           }        private WindowsImpersonationContext impersonationContext = null;        // ------------------------------------------------------------------        #endregion    }    /////////////////////////////////////////////////////////////////////////}

I just spent the day fixing this for myself.

I finally was able to make it work by adding -Scope Process to Set-ExecutionPolicy

invoker.Invoke("Set-ExecutionPolicy Unrestricted -Scope Process"); 

Several PowerShell cmddlets take a PSCredential object to run using a particular user account. May have a look at this article -http://letitknow.wordpress.com/2011/06/20/run-powershell-script-using-another-account/

Here's how you can create the Credential object containing the username and password you want to use:

$username = 'domain\user'$password = 'something'$cred = New-Object System.Management.Automation.PSCredential -ArgumentList @($username,(ConvertTo-SecureString -String $password -AsPlainText -Force))

Once you have the password ready for use in a credential object, you can do a number of things, such as call Start-Process to launch PowerShell.exe, specifying the credential in the -Credential parameter, or Invoke-Command to invoke a "remote" command locally, specifying the credential in the -Credential parameter, or you could call Start-Job to do the work as a background job, passing the credentials you want into the -Credential parameter.

See here , here & in msdn for more information