[lilyl]

bought new scomputer ofr my mother which had been tested with Vista Home Basic. We purchased separately Home Premium but unable to install because only screen message asking for Product Key for Basic to activate. The Product Key for Premium not accepted

[good grief]

When typing in the product key did you type in the dashes? If so, leave them out as it will put them in itself.

[lilyl]

Thans I tried that but no success

[good grief]

Ok, then you might need to wait for someone else to suggest something. Did you buy the Home Premium online or at a shop? If it was at a shop, maybe give them a call, they may be able to suggest something. Otherwise possibly ring Microsoft and explain the situation, and they should be able to help. Good luck getting it sorted out.