Microsoft on Thursday h its fiscal Q4 2013 earnings, with some impressive results, but it more notably showed a massive $900 million loss during the quarter because of Surface RT "inventory adjustments".

Read: Microsoft Surface RT tablet prices dramatically dropped worldwide

Microsoft apparently built too many Surface RTs, suggesting the company didn't sell as many tablets as it wanted, although the loss affected only the total revenue for Windows. Despite the steep dip, Windows still showed a year-on-year revenue increase thanks to the Windows 8.

It's worth noting that the news of Microsoft's loss comes a few days after Surface RT tablet prices dramatically dropped worldwide. CNET reported that price cuts and increased distribution were to blame for the nearly $1 billion loss.

However, TechCrunch called the Surface RT a "dog" on Thursday. The tech website said it was "very hard to find a positive review of Windows RT, and more specifically, the nine-month-old Microsoft Surface with RT". With that said, Microsoft Surface sales were supposedly on the up-and-up during the first quarter of 2013.

Read: Microsoft Surface sales reached 900,000 in Q1, joining top 5 tablets

According to IDC in May, Surface Pro and Surface RT tablets combined for a total 900,000 units shipped during the first quarter. Stay tuned, though, as Microsoft might provide more information during its earnings call this afternoon.