Microsoft has apparently admitted that it will not hit its target for 1 billion Windows 10 users by fiscal 2018, with its mobile weakness playing a role in this.

According to a statement provided to ZDnet, while the platform is “off to the hottest start in history with over 350 million monthly active devices, with record customer satisfaction and engagement”, the “focusing” of Microsoft’s smartphone hardware business means it will take longer to reach the milestone.

Since its acquisition of Nokia’s devices unit, Microsoft has struggled to make a go of the business, to the point it has almost – if not completely – exited the market. While the company has said that Windows 10 in its mobile guise is not an immediate priority, this has now impacted its ability to reach its self-generated Windows 10 user target.

Aside from Microsoft’s own mobile activities, the company has also failed to generate much traction for Windows 10 Mobile among other hardware partners – certainly at the top table. This means it is effectively closed out of the biggest sector for smart device platforms, making it difficult to rapidly grow user numbers.

But on a more positive note, it is seeing support in the high-end, productivity-focused tablet and 2-in-1 market.

While Microsoft has been able to drive Windows 10 adoption with free upgrades for users of earlier platforms, it has come in for criticism about the somewhat aggressive way in which it has done this. Looking forward, as free upgrades are no longer available as a growth driver, the company will be working primarily in a PC and tablet market that looks lacklustre, even when compared with the stagnant mobile market.