bool IsUserAdmin(){
/*++
Routine Description: This routine returns TRUE if the caller's
process is a member of the Administrators local group. Caller is NOT
expected to be impersonating anyone and is expected to be able to
open its own process and process token.
Arguments: None.
Return Value:
   TRUE - Caller has Administrators local group.
   FALSE - Caller does not have Administrators local group. --
*/

BOOL b;
SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
PSID AdministratorsGroup;
b = AllocateAndInitializeSid(
    &NtAuthority,
    2,
    SECURITY_BUILTIN_DOMAIN_RID,
    DOMAIN_ALIAS_RID_ADMINS,
    0, 0, 0, 0, 0, 0,
    &AdministratorsGroup);
if(b)
{
    if (!CheckTokenMembership( NULL, AdministratorsGroup, &b))
    {
         b = FALSE;
    }
    FreeSid(AdministratorsGroup);
}

return(b);
}