Microsoft  just 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, Best Buy, Staples, Office Depot and the Microsoft Store, among other locations.  Microsoft says 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.  The upgrade promotion for Windows 8 Pro runs online and at retail locations until January 31st, 2013.