Microsoft reverses adult game ban on Windows 8
Assassin's Creed, Mass Effect, Skyrim and other mature games will no longer be banned from the European Windows 8 Store.
The store is the official outlet for programs Microsoft has tested to ensure they work with Windows 8.
A mismatch in the US and Europe over game ratings led to the games' exclusion outside North America.
Microsoft has relaxed its restrictions so the titles will be tested to work on PCs and tablets running Windows 8.
In the US games such as Call of Duty, Skyrim and Mass Effect typically win a "mature" rating under its ESRB system. This means anyone aged 17 and over can play them.
By contrast in Europe these titles and many others are marked as Pegi 18 which means only adults can buy and play them.
Before now Microsoft operated a blanket ban on adult-only content on its Windows 8 Store.
"It basically ends up disqualifying games that would be ESRB Mature," Antoine Leblond, Microsoft corporate vice president of web services told tech news site Gizmodo.
This had the potential to cause problems on desktop PCs and laptops as it would have meant that the games would not be certified as working with Microsoft's new operating system. The games would also not be promoted via the Windows Store.
The Windows 8 testing and certification system has won criticism from many games makers. Markus Persson, creator of Minecraft, said it risked turning the PC into a closed platform. Gabe Newell, head of game maker Valve, said Windows 8 could be a "catastrophe" for it and other developers.
Games that do go through the testing and certification process are likely to work with Windows 8 though users will have to find and install the titles themselves.
However, the ban could have caused bigger problems with Windows RT. This is the version of Windows 8 meant for tablets and the only way to get software for it is via the store. This is to ensure the programs work well with touchscreen interfaces typically found on tablets.
Relaxing the rules means the games can now get into the Windows Store and be guaranteed to run on Windows 8 be it running on a PC or tablet.
The change is due to come into force by the end of 2012, Mr Leblond told Gizmodo.