I’ve been asked a couple times lately what users can do to return their PC to that ‘brand new’ performance level.
Well, first a bit of bad news — No software will do this for you, no matter what it claims. That’s why, for both security and performance, I recommend, at a minimum, yearly Windows re-installs. Full, new, clean installs – no repairs, etc..
Of course, first thing you should install is Process Lasso and your favorite browser, then make sure you adhere to good and safe usage habits. Don’t install crap with bundles. Don’t install anything that’s unsigned, unless you are really, really sure about it.
I don’t recommend third-party security suites because they reduce performance, and Windows Defender is built-in, though it’s so quiet you may never notice. After all, if security suites were really effective, there wouldn’t be a malware problem, would there? I think their real-world malware detection rate is around 40% at last estimate. They do manage high rates of false positives though. Windows Defender has one of the best track records when it comes to false positive rate, perhaps because they have no interest in selling you anything, so don’t need to scare you over benign objects on your PC.
This will also ensure you have proper data backup habits.
As a side note, if you store your data in the Cloud, use BoxCryptor (I have no affiliation). It enables transparent client-side encryption of data stored to *any* cloud provider, from DropBox to OneDrive, and even supports filename encryption.