Yes, by giving IE away for free while bundling it with Windows, at a time when Netscape was trying to sell their browser - basically the polar opposite of what Google and Apple are doing with their app stores.

Since then, it has become completely expected that any consumer OS includes a bundled web browser for free.

Not that MS is not doing many other shady things to try to control what you do and push their products in today's Windows, mind you. The only point is that, as bad as consumer computing was in the 90s, it's much much worse today in terms of user and developer freedom/choice.

Microsoft never prevented you from installing anything you like on their OS.

This is true, but what Google do with the play store (install it by default, take 30% of everything, make it hard to install without it) is so much worse.

And Apple's app store where you can't even get around it if you want to is an order of magnitude worse again.