Microsoft (MSFT) on Friday announced that consumers can now reserve an upgrade copy of Windows 8 Pro at select retailers. In the United States, the software will be available for $69.99 at Amazon (AMZN), Best Buy (BBY), Staples (SPLS), Office Depot (ODP) and the Microsoft Store, among other locations. The company notes that users will be able to upgrade to Windows 8 Pro online on or after October 26th with Microsoft’s Upgrade Assistant for only $39.99, however. The upgrade promotion for Windows 8 Pro runs online and at retail locations until January 31st, 2013.