Microsoft has traditionally sold full, upgrade, and OEM System Builder editions of Windows at retailers. But according to Windows Weekly co-hosts Paul Thurrott and Mary Jo Foley, the company is planning to change how it distributes its operating system, ditching the full retail version of Windows 8 this time around in favor of the presumably cheaper OEM option for home users building a PC.

In the past these licenses were intended for small-scale system builders and supposed to be sold by retailers with a piece of hardware --- but many including Newegg and Amazon have offered it as a standalone purchase. Unlike full retail copies of the OS, they offered no phone support or fancy boxes, and in theory banned users from transferring the operating system from one PC to another.

It's unclear if the same restrictions will apply once full retail editions of Windows are no longer available and if Microsoft sell these System Builder editions at the same relative low-prices it has in the past – for reference, the OEM edition of Windows 7 Home Premium was priced at $110, nearly 50% off Microsoft's list price of $200 for the full version and about 10% less than the $120 price of the upgrade.

So far Microsoft has only revealed the special promotional price for users running XP, Windows Vista and Windows 7 to upgrade to Windows 8 Pro, which is set at a mere $39.99 through January 31, 2013. Also, those who bought a Windows 7 PC after June 2 will be able to upgrade to Windows 8 Pro for $14.99.