Windows 10 Mobile requires a whopping 8GB of internal storage
This is an issue because multiple current Windows handsets, including the Nokia Lumia 530 and the HTC 8S, have just 4GB of internal storage.
Windows Insiders, the programme that Microsoft ran to help test its new operating system, discovered that early versions of Windows 10 Mobile required more than 4GB - and it now seems the full OS requires double that.
The release of Windows 10 Mobile, the successor to Windows Phone 8, is imminent. But Microsoft has remained relatively quiet about the requirements to run the new software, who will get it (beyond a list of Nokia phones that ignores the high-end models), and whether carriers have any say in the roll-out.
Requiring more than 8GB of internal storage space is a strange move by Microsoft. It has seen its largest market share gains from low-end phones in emerging markets, many of which won't own more expensive devices with the space required to load Windows 10 Mobile. This, in turn, could create fragmentation as the majority of users retain Windows Phone 8 and some high-end users get Windows 10 Mobile - a problem that has blighted Google's Android OS for years.
When Apple released iOS 8 the software required 5GB of free space to install - a figure the company later rolled back to 1.1GB when users protested that they simply could not clear enough space. We may see Microsoft may end up in a similar position.
Business Insider has reached out to Microsoft for comment and will update when it responds.