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.

Best computer cleaning software