Microsoft said it was starting the project to update millions of machines to improve security online.
Future updates to the browser would be applied without a user’s knowledge to help beat scammers catching people out with fake updates.
Those who did not want their browser updated could opt out or uninstall the software, said Microsoft.
"The Web overall is better – and safer – when more people run the most up-to-date browser," wrote Ryan Gavin, Microsoft’s IE boss, in a blogpost explaining the plan.
He said the data gathered by Microsoft for its security intelligence reports showed that many cyber criminals targeted old or outdated software when they tried to trick people into installing fake updates.