There are a few more specific restrictions, like cross-architecture upgrades - 32bit XP, Vista, and 7 users can only upgrade to 32 bit Windows 8, and likewise for 64 bit Windows. Customers that do have SP1 will have their system settings transferred as well.
Customers running Windows 7 Pro or Enterprise editions can update to Windows 8 Enterprise with system settings, personal files, and applications intact.Users running Windows 7 Starter, Home Basic, Home Premium, and Professional will be able to upgrade to Windows 8 Pro with system settings, personal files, and applications intact.Users running Windows 7 Starter, Home Basic, or Home Premium can upgrade to Windows 8 with their system settings, personal files, and applications intact.The news is mostly good: Windows XP, Vista, and 7 customers can all upgrade to Windows 8, but there are some restrictions. According to ZDNET, Microsoft has detailed its Windows 8 upgrade plans to select partners.
