just as an addition to the above i have run all the tests with 4 other laptops on my Home Wi-Fi , speedtest etc
File Transfers to a NAS and other networked PCs ,interference etc. and read everything available on the issue on the Net Forums etc. that is available.
The choice before this purchase was between this and a Macbook Pro. i WAS and AM delighted with my choice if this problem could be resolved, then DELL would be on a winner this s a very nice laptop.