HONG KONG — A Chinese regulator said Tuesday it would open a new antitrust investigation of Microsoft, related to electronic data the government collected as part of an earlier inquiry.

Despite Microsoft’s recent steps to improve relations with the Chinese government, the announcement is a reminder of the regulatory challenges that multinational companies face in the country, one of the world’s largest technology and consumer markets.

The new scrutiny of Microsoft by the regulator, the State Administration for Industry and Commerce — known as SAIC — stems from antitrust investigations of major Western tech companies in 2014.

In July of that year, about 100 SAIC officials stormed four Microsoft offices in China, questioning executives, copying contracts and records, and downloading data from the company’s servers, including e-mail and other internal communications.

The Chinese regulator said it was seeking answers to “major questions’’ that arose from the data but did not provide any further details of the investigation Tuesday. Analysts have said Microsoft’s difficulties in China began in 2014, when the company decided to end support and security updates for Windows XP, an aging software line that it hoped users would replace by upgrading to Windows 10 or other recent operating systems.

A Microsoft spokesman, who spoke on the condition of anonymity, said Tuesday the company was “serious about complying with China’s laws and committed to addressing SAIC’s questions and concerns.’’