You upgrade the VMs (or partitions, like a second boot partition on a PC, or Boot Camp on OS X) the same way someone upgrades a physical machine: by running the Windows 8 Upgrade Assistant on Windows.com.
Any chance that the System Builder SKUs will fall in price after Oct. 26? We don't think so.
The list prices for the Windows 7 Home Premium and Windows 7 Professional System Builder equivalents are $128 and $179, respectively, according to Amazon. Not surprisingly, Amazon's prices are less: $92 and $128, or close to the Windows 8 System Builder prices on Newegg.
In other words, unless Microsoft drastically reduces the list price of System Builder, the numbers on Newegg are probably the discounted prices.
How much to upgrade a new Windows 8 system to Windows 8 Pro? $69.99 during the discount stretch.
Microsoft's calling this the "Windows 8 Pro Pack;" It consists of an activation code that turns Windows 8 into Windows 8 Pro. The Pro Pack is analogous to the in-place upgrades the company touted as "Anytime Upgrades" for Windows 7.
Newegg said the Pro Pack's $69.99 price was a $30 savings over the regular price of $99.99, with the latter presumably the upgrade's eventual list price. If so, that's a $10 increase over the Windows 7 Home Premium Anytime Upgrade to Windows 7 Professional, which costs $89.99.
It may be cheaper to buy the new PC with Windows 8 Pro already installed, if the option's offered. Sony, for example, charges an additional $50 to bump up a pre-ordered Windows 8 notebook to Windows 8 Pro. ( Dell, on the other hand, adds the same $70 as the price for the Windows 8 Pro Pack to juice a Windows 8 machine to Windows 8 Pro.)
What about Windows 8? What will it cost to upgrade to the consumer version, rather than Windows 8 Pro We don't know because Microsoft's not saying.
Among the blank spots in an imaginary Windows 8 pricing chart are those for the entry-level edition. So far, Microsoft's only talked about upgrades to Windows 8 Pro.
The company may be waiting until Oct. 26 to divulge a price for a Windows 8 upgrade, or dawdling until early next year, after the discounted $39.99 Windows 8 Pro upgrade offer expires.
Or the omission may mean more. It's possible that Microsoft won't even bother to sell an upgrade to Windows 8, leaving that SKU to OEMs to pre-install on their least-expensive consumer PCs, and to the System Builder line.