Joshua Erdman, president of Digital Foundation Inc., a San Luis Obispo, Calif.-based reseller, said that WGA's mistakes disproportionately occur among PCs owned by gamers and other techies. They tend to install upgrades such as new processors, memory or hard drives, which throws WGA's ID technology off.

In contrast, most companies are either large enough to buy volume licenses from Microsoft, which are less affected by WGA, or don't do such hardware upgrades, Erdman said.

"For businesses, a PC is just a tool. They rarely upgrade their machines," Erdman said.