Microsoft has announced the availability of Internet Explorer 10 as a Release Preview edition – in both 32-bit and 64-bit flavours – for Windows 7. (And yes, only Windows 7 users with SP1 installed need apply. Windows Vista and XP are left out of this one.)

Changes are mostly under the hood, but the upgrade does deliver some major performance improvements which you may like to try.

In our first tests, the new Release Preview installed much like any other Windows update. It downloads a few files, and whirs for a while before demanding a reboot. Which takes a little longer than usual as various core files are replaced.

And the relaunch revealed another problem, as IE10 immediately complained that it wasn’t connected to the internet. This turned out not to be a Microsoft problem, but was rather down to our firewall blocking the browser, presumably because the executable had changed.

The new interface hasn't changed much, but there are useful performance improvements under the hood

With our security software duly tweaked, though, the browser ran as normal, and aside from a new Help > About dialog looked almost exactly as it did before. Forget any pictures you’ve seen of the Metro IE 10 running under Windows 8; there are very few visual differences from IE9.

Look closely and you will find some new features, if with the occasional catch.

Enhanced Protected Mode further isolates the browser to limit what malware can do, for instance, and can be enabled at Tools > Internet Options > Advanced > Security. But this will disable any extensions which aren’t compatible with the new technology, so test it with care.

And Do Not Track is now enabled by default, supposedly to enhance your privacy. But as some companies have said they’ll ignore this as it’s not based on a user decision to opt out, the setting’s usefulness isn’t yet clear.

The real benefit here is in performance, then, where an upgraded Javascript engine, assorted rendering improvements and other tweaks give Internet Explorer 10 Release Preview a major performance boost over IE9. And if you’re a regular IE user then that alone is probably enough to justify the early update.