I got am question.

Now, I already know which edition of Vista is suitable for me, and I will target Ultimate Edition.

However, I saw one sells online with quite a cheap price, in US, and I plan to buy from him. But I notice 1 different between US and International Vista.

SKU code for United States is 66R-00002, while in countries other than US is 66R-00020. What is the different? Is there any geographical limitation? And the most important is, can I activate it in Malaysia and use it like normal?
I search for a lots of forums and websites and blogs, but I just can't find any answer for it. Hope someone can answer my questions, instead keep telling me to buy from Malaysia.....

Thank you!