Microsoft has announced a new Windows 8.1 version for OEMs to preinstall. "Windows 8.1 with Bing," as it is known, appears to be identical in every way to regular Windows 8.1, with one exception: OEMs have to leave the system defaulting to using the Bing search engine.

Windows 8.1 already defaults to using Bing, but OEMs can change that default if they choose. In the Bing edition, they cannot.

The new version is only available to OEMs for preinstallation, and it may also be combined with Office or a one-year Office 365 subscription.

The company does not actually come out and say it, but the implication is that Windows 8.1 with Bing is cheaper than regular Windows. This will give OEMs a low-cost Windows option for devices that aren't eligible for a zero-cost Windows license—namely, those with screens larger than 9 inches. The Bing edition is the latest effort to cut Windows' pricing and enable correspondingly lower hardware prices.