Microsoft has been accused of changing the pop-up box asking Windows users to upgrade to Windows 10 to schedule the upgrade if the red “close” cross is clicked.

According to the BBC, clicking on the cross button on the pop-up window results in the upgrade being scheduled instead of the prompt being dismissed.

The publication quoted industry experts as calling this a “dirty trick”.

The upgrade could still be cancelled when the scheduled time for it to begin appeared, said Microsoft in response to complaints.

“With the free Windows 10 upgrade offer ending on 29 July, we want to help people upgrade to the best version of Windows,” said Microsoft.