EU data regulators are concerned about user data processing, after Microsoft failed to do enough to address their concerns about the collection and processing of user data with changes made to Windows 10 last month.

European Union data-protection officials sent a letter to Microsoft saying they remain "concerned about the level of protection of users' personal data," according to a the document. Regulators from seven countries are concerned that even after the announced changes, "Microsoft does not comply with fundamental privacy rules."

EU regulators, who meet on a monthly basis, sent the letter to Microsoft Chief Executive Officer Satya Nadella and Chief Privacy Officer Brendon Lynch on Feb. 15.

Microsoft is "listening carefully to comments from members" of the EU group of privacy authorities and "will continue to cooperate with the Working Party and national data protection agencies," it said in a statement Tuesday.

Google and Facebook have also faced an increasing number of regulatory fences as EU watchdogs seek to curb unwarranted processing of people's personal data.

Data-protection agencies from the Netherlands, Germany, France, the U.K., Spain, Hungary and Slovenia are collaborating on the Microsoft probes, a Dutch watchdog said Tuesday.