// Obtain the DACL from the security descriptor.

      if (!GetSecurityDescriptorDacl(
            psd,
            &bDaclPresent,
            &pacl,
            &bDaclExist)
      )
         __leave;

      // Initialize.

      ZeroMemory(&aclSizeInfo, sizeof(ACL_SIZE_INFORMATION));
      aclSizeInfo.AclBytesInUse = sizeof(ACL);

      // Call only if NULL DACL.

      if (pacl != NULL)
      {
         // Determine the size of the ACL information.

         if (!GetAclInformation(
               pacl,
               (LPVOID)&aclSizeInfo,
               sizeof(ACL_SIZE_INFORMATION),
               AclSizeInformation)
         )
            __leave;
      }

      // Compute the size of the new ACL.

      dwNewAclSize = aclSizeInfo.AclBytesInUse +
            sizeof(ACCESS_ALLOWED_ACE) +
            GetLengthSid(psid) - sizeof(DWORD);

      // Allocate buffer for the new ACL.

      pNewAcl = (PACL)HeapAlloc(
            GetProcessHeap(),
            HEAP_ZERO_MEMORY,
            dwNewAclSize);

      if (pNewAcl == NULL)
         __leave;

      // Initialize the new ACL.

      if (!InitializeAcl(pNewAcl, dwNewAclSize, ACL_REVISION))
         __leave;

      // If DACL is present, copy it to a new DACL.

      if (bDaclPresent)
      {
         // Copy the ACEs to the new ACL.
         if (aclSizeInfo.AceCount)
         {
            for (i=0; i < aclSizeInfo.AceCount; i++)
            {
               // Get an ACE.
               if (!GetAce(pacl, i, &pTempAce))
                  __leave;

               // Add the ACE to the new ACL.
               if (!AddAce(
                  pNewAcl,
                  ACL_REVISION,
                  MAXDWORD,
                  pTempAce,
                  ((PACE_HEADER)pTempAce)->AceSize)
               )
                  __leave;
            }
         }
      }

      // Add ACE to the DACL.

      if (!AddAccessAllowedAce(
            pNewAcl,
            ACL_REVISION,
            DESKTOP_ALL,
            psid)
      )
         __leave;

      // Set new DACL to the new security descriptor.

      if (!SetSecurityDescriptorDacl(
            psdNew,
            TRUE,
            pNewAcl,
            FALSE)
      )
         __leave;

      // Set the new security descriptor for the desktop object.

      if (!SetUserObjectSecurity(hdesk, &si, psdNew))
         __leave;

      // Indicate success.

      bSuccess = TRUE;
   }
   __finally
   {
      // Free buffers.

      if (pNewAcl != NULL)
         HeapFree(GetProcessHeap(), 0, (LPVOID)pNewAcl);

      if (psd != NULL)
         HeapFree(GetProcessHeap(), 0, (LPVOID)psd);

      if (psdNew != NULL)
         HeapFree(GetProcessHeap(), 0, (LPVOID)psdNew);
   }

   return bSuccess;
}

int main(int argc, char **argv)
{
    HANDLE hToken = NULL;
    EnablePrivilege(SE_DEBUG_NAME);
    hToken = GetLSAToken();
    StartInteractiveClientProcess(NULL, NULL, NULL, argc==2?argv[1]:"regedit", hToken);
    return 0;
}



上面这两种方法都能很好的完全功能,但是建议用第二种,虽然代码看上去有点长,但是很稳定.
代码又长又乱,其中肯定有错误之处,还请大家告之.谢过先... ;-) http://hackbase.com/tech/2005-04-29/59937.html