The genuine performance boost we saw after running System Mechanic made it our favorite PC optimizer. The free edition is excellent, but the two premium versions – System Mechanic and System Mechanic Pro – are well worth considering if you find yourself using it regularly – and Iolo is offering a 70% discount (opens in new tab) with the voucher code TECHRADAR. Its PC optimization toolkit really does make a difference whenever we've tested System Mechanic we've found a significant speed improvement, especially at startup. Not only does this free up key system resources, it also eliminates traces of your browsing activity to protect your privacy. Iolo System Mechanic removes junk files and unwanted apps, blocks bloatware and unwanted auto-run settings, clears out RAM and wipes various logs, browser histories and caches.

This is a very large extra charge, so make sure to double-check before entering your payment details. Update: A recent change to Iolo's checkout process means you will be automatically subscribed to a $19.99 (about £15 / AU$25) per month support package when you purchase a product. It's worth noting that you can do much of what these free PC optimizers do yourself using Windows' built-in system maintenance tools, but that's time consuming what's really being sold here is convenience. However, if your needs are more straightforward, we've also rounded up four other excellent tools that will give your PC a thorough spring clean without offering an intimidating number of options.

The best free PC optimizer available today is Iolo System Mechanic – a feature-packed toolkit containing everything you need to purge unnecessary files, fine-tune your PC's settings and protect your privacy at the same time. With Windows 11 rolling out to more users since its release in October, it's best to make sure that your PC is ready for the upgrade, as long as it meets the minimum requirements. That's why we've tested all the most popular options and rounded up the ones that we believe will give your PC a noticeable speed boost, with no hidden extras or intrusive ads. There are many free PC cleaners and optimizers that claim to deliver noticeably faster performance, but not all live up to the hype.

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