First of only data I saw was the NPD data saying "11% decrease in laptop sales in the US retail" None of these track the exisitng PC upgrades and also all thw data I have seen only seem to focus on US markets and that too US retail. Doesn't cover world markets, tablets and may not even cover oninesale (micrsofot store, online store, surfacr sales)I haven't seen anything related to worldwide data. When enterprises toll-out win7 and win8 it doesn't mean that they buy new laptops automatically, they may choose to upgrade existing hardware.
Micrsofot had a gangbuster quarter with 120Million Windows sales (60M Win8 and likely 60M win7) and you multiply that between 40 to 50 average sellingprice and you can see it was a 4.8B to 6B quarter just on windows. Add Surface, previous qurster recognition etc... Windows divsion likely grew 87% - 100% sequentially. December quarter was a block buster Q. Make no mistake.