British consumer rights group Which? isn't very happy with the way that Microsoft has handled Windows 10. The group says that Microsoft should compensate Windows 10 users for when the upgrade caused downtime due to software or hardware incompatibility, and it needs to do more to ensure that Windows users are aware of the customer support options that are available to them.

This comes after a June survey of Windows users showed that 12 percent of upgraders reverted back to Windows 7 or 8.1, with a majority of those downgraders saying that the upgrade adversely affected their PC.

The group cited a laundry list of complaints about the upgrade, with most of the complaints boiling down to compatibility issues. Hardware compatibility was a particular problem, with devices such as printers and Wi-Fi adapters ceasing to function after installing Windows 10. This points at one of the more unsatisfactory aspects of the upgrade. Although in principle the upgrade should have verified that there were no compatibility issues (both hardware and software), there are numerous reports that this didn't work in practice, with the upgrade being pushed to machines that were then left partially inoperable as a result.

Incompatibility is particularly problematic when the computers' Wi-Fi adapters break because of the upgrade; machines are then unable to get online, making them particularly difficult to diagnose and troubleshoot. Even if a problem can be fixed by downloading a new driver, a system that can't get online obviously can't do that.

Which? also reported that the Windows 10 upgrade would uninstall some software, including unspecified Norton software and Microsoft's own Office 2010. The group said that this was a problem if users had lost their original product keys or install media, as it could leave them with no alternative but to repurchase the software.

Perhaps worst of all, some users say that they had to pay for third-party repairs to get their systems operational again after the upgrade.

Microsoft does offer free tech support to upgraders, both over the phone and online, but Which? says that Windows users who have had problems have struggled to contact the company, either failing to find the right contact information or being discouraged by the abundant tech support scammers out there.

Accordingly, Which? is calling on the company to do much more to promote awareness of the free tech support options and to offer compensation to those Windows users adversely affected by the upgrade, claiming that users are entitled to this under the Consumer Rights Act of 2015.