Hi, 

I have to reinstall a Studio XPS M1640 for a friend, which was natively a vista, and now a windows 7 64 bits.
I have the OEM windows key and Service Tag for this computer if needed.

I tried to go to microsoft to get the iso but it's not working 

and tried https://www.dell.com/support/home/fr/fr/frbsdt1/drivers/osiso/win

where I get this message :  " Recovery image currently unavailable."

What should I do ? is it possible to upgrade to windows 10 instead of the "dead" windows 7 ?

Best Regards

Zoltan