Genuine Windows Activation?

I recently had Windows 7 Ultimate installed on my laptop, in a computer service shop.
They assured me it was legitimate. But now when I installed the latest updates, I get the continual
message. "This copy of Windows is not genuine". I cannot find a Microsoft site that will resolve this,
even after much searching.
I am willing to pay for a Windows license if needed. If that would validate my current copy and avoid a
re-install, is that possible?
All advice welcome, Thank you.

Hi Dorian,
run this tool
http://go.microsoft.com/fwlink/?LinkID=52012

It should tell me why its showing, non genuine
Then go back to the shop tell him your gonna report him to MS, and your local Trading Standards, thats what we call it here Blighty dont know yours?

Not sure if youll be able to get a genuine Ultimate, if you do then you just have to insert the new key
controlpanel >> system >> change product key.

Roy

Thank you for the reply. I ran the tool as you suggested. I don't understand the results.
Can't seem to get the resulting document attached here either.

Thank you for the reply. I found this site, not sure how legitimate it is, any ideas?
Genunine Windows 7 Ultimate SP1 Product Key Download