Setting Date and Time on Windows Embedded Standard 7 OS

I am working on setting Date and Time on Windows Embedded Standard 7 OS using C# .net.

I tried changing the system date using code in following link.

http://www.pinvoke.net/default.aspx/kernel32.setsystemtime

But I also saw that one should get the privileges to change the same. But I am receiving an error. here is the code to

Privileges.EnablePrivilege(SecurityEntity.SE_SYSTEMTIME_NAME);

        if (SetSystemTime(ref st) == 0)
        {
            return 0;
        }
        return 1;

For getting the privaleges I used the code from the following link.

http://www.pinvoke.net/default.aspx/advapi32/AdjustTokenPrivileges.html C# Sample Code 2 (With full error handling):

I have question: Is it possible to change the Date and Time using PInvoke. If it is possible what are the change/Setting I should do at the OS.

And what are the other ways to change the date and time.

thank you

Edit:

[DllImport("kernel32.dll")]
    extern static uint SetSystemTime(ref SYSTEMTIME lpSystemTime);


    public int SetSystemDateTime(DateTime NewSystemDateTime)
    {
        SYSTEMTIME st = new SYSTEMTIME();
        st.wYear = (ushort)NewSystemDateTime.Year;
        st.wMonth = (ushort)NewSystemDateTime.Month;
        st.wDay = (ushort)NewSystemDateTime.Day;
        st.wHour = (ushort)NewSystemDateTime.Hour;
        st.wMinute = (ushort)NewSystemDateTime.Minute;
        st.wMilliseconds = (ushort)NewSystemDateTime.Millisecond;

        Privileges.EnablePrivilege(SecurityEntity.SE_SYSTEMTIME_NAME);

        if (SetSystemTime(ref st) == 0)
        {
            return 0;
        }
        return 1;

    }

I finally found the solution. Code in the following link works fine for me: http://www.pinvoke.net/default.aspx/kernel32/SetLocalTime.html

Also following code I found in one of the posts in stackoverflow, helped me.

using System.Security.Principal;
    bool IsUserAdministrator()
     {             
        bool isAdmin;
        try
        {
            WindowsIdentity user = WindowsIdentity.GetCurrent();
            WindowsPrincipal principal = new WindowsPrincipal(user);
            isAdmin = principal.IsInRole(WindowsBuiltInRole.Administrator);
        }
        catch (UnauthorizedAccessException ex)
        {
            isAdmin = false;
        }
        catch (Exception ex)
        {
            isAdmin = false;
        }
        return isAdmin;
    }