Windows 10 users have discovered another bug with the flagship Microsoft OS.

The leading PC operating system suffered a high-profile problem after fans reported a major issue with the October 2018 update last month.

That bug lead to Windows 10 users experiencing instances of unexpected file deletion.

This prompted Microsoft to pause the rollout of the Windows 10 October 2018 update, with it still yet to be released to all users.

And now another issue with the Microsoft OS has been discovered by PC fans.

As reported in a post by How To Geek, a “strange bug” has been discovered in Windows 10.

This bug means file associations no longer work properly on Windows 10.

So, this means if you try to select certain applications as a default in Windows 10 then you won’t be able to.

How To Geek tested multiple PCs running Windows 10 and all stations ran into the issue.

The site’s tests found that the issue popped up with certain applications but not others.

For instance, Windows 10 wouldn’t let users make Adobe Photoshop or Notepad++ a default for images or text files.

But other applications, like Google Chrome, could be made defaults.

In their article How To Geek wrote: “We’ve tested multiple Windows 10 PCs running the April 2018 Update and every single one we tested has this problem.

“It doesn’t affect every application, but it does at least affect Photoshop and Notepad++.

“This bug does not appear to affect PCs running the October 2018 Update, which was pulled because of multiple data loss bugs and has not yet been re-released.

“Based on our research and various social media posts we’ve found, our theory is that this stopped working properly when Microsoft released the KB4462919 update on October 9.

“But we really don’t know. It’s broken on the stable version of Windows 10 today and it’s probably been broken for a while. This definitely used to work.”

In other Windows 10 news, Microsoft has been dealt some good news after the troubles with the October 2018 update.

Windows 10 is reaching a crossover point with Windows 7 – the most popular OS in the world.

Stats from California-based Net Applications put Windows 10 right behind Windows 7 in October 2018.

Their stats show Windows 10 running on 38.3 per cent of all PCs in October, with Windows 7 just ahead on 39.4 per cent.

Likewise, stats from the NetMarketShare analytical website also put Windows 10 within touching distance of Windows 7.

Their stats show Windows 7 is the leading operating system in the world, used on 39.35 per cent of computers in October.

However, Windows 10 is just behind on 38.28 per cent.

This is a huge turnaround compared to last year.

Looking at October 2017 figures, NetMarketShare then had Windows 7 holding a mighty 43.05 per cent share of the OS market.

Whereas Windows 10 then had a 29.86 per cent market share.