Read this and answer the question. If the question is unanswerable, say "unanswerable".

In March 2013, Microsoft also amended its certification requirements to allow tablets to use the 1024×768 resolution as a minimum; this change is expected to allow the production of certified Windows 8 tablets in smaller form factors—a market which is currently dominated by Android-based tablets. Despite the reaction of industry experts, Microsoft reported that they had sold 100 million licenses in the first six months. This matched sales of Windows 7 over a similar period. This statistic includes shipments to channel warehouses which now need to be sold in order to make way for new shipments.

What changes did Microsoft make to its recertification requirements in March 2013?
unanswerable