Not sure if this is the right place to post this query. I know there are plenty of sites the clean and speed up your PC at a price,do we have anywhere that does it for free, thanks
Malwarebytes, as said above, is great. However it doesnt protect your PC 24/7 unless you get the paid version. But it works wonders for virus infections none the less.
However thats not all you need. The last step is a good defrag program. Windows offers one with every OS but it doesnt typically do that great of a job. Try defargler. I havent used it personally but its free and made by a proven reliable company.
I also agree on using CCleaner and Defraggler. I use them both and get 100% maximum possible performance from my PC at all times.
You do not need to pay to get good quality software. In fact, the paid stuff is usually of poor quality. Free, high quality software is all over the internet. You only need to know where to look ;P