The consumers’ organisation Which? launched a campaign to force the US company to act, after a survey of 5,500 users revealed that more than one in ten had been forced to uninstall their new copies of the software.
Half said the update had “adversely affected” their PCs.
Which? said it had received hundreds of complaints about Windows 10, and called on Microsoft to “honour consumers’ rights, including paying compensation where it’s due”.
The organisation said many users had complained of being “nagged” by Microsoft about the new update, which had then installed itself against their wishes.
Other problems included printers, internet connections and speakers no longer working, files getting lost and email accounts no longer updating. In some cases, users had to pay repairers to rectify the damage.
There were further complaints about poor customer service from Microsoft when users contacted the company.
Which? said it was calling on Microsoft to improve its customer service and repair and compensate customers where appropriate.
Alex Neill, director of campaigns and policy, said: “We rely heavily on our computers to carry out daily activities so, when they stop working, it is frustrating and stressful. Many people are having issues with Windows 10 and we believe Microsoft should be doing more to fix the problem.”
Mr Neill said consumers had the same legal rights when buying software as with other goods.
“If the content is faulty you’re entitled to a repair or replacement,” Which? said.
Mircosoft defended its upgrade policy. A spokesman said: “The Windows 10 upgrade is a choice designed to help people take advantage of the most secure, and most productive Windows. Customers have distinct options. Should a customer need help with the upgrade experience, we have numerous options including free customer support.”