vista to windows 7 upgrade

[gumboot]

I'm a bit confused about upgrading from my genuine vista home premium installation to windows 7. On this website:

http://www.computerac...pgrade-vista-windows7

it says that the PC must have vista SP1 installed. My PC only indicates that it has vista SP2 installed in the window shown in the video. I don't know if it has SP1 installed. I can't seem to find on the internet why SP1 is so important for the upgrade. Does anyone know anything about this please?

Many thanks

[gumboot]

Sorry, I didn't make clear that you need to run the video in the link from beginning to end. It's all in the commentary.

[rojash]

If you SP2 then effectively you also have SP1.
What it means is that you must have AT LEAST SP1

[rojash]

sorry: should read If you have SP2 then...