Fortress Of Good Fortune

You should be able to make to do most of it without a PC cleaner (which are mostly malware or a waste of money).

Run your malware and virus checkers. Delete any of any files that have been 'locked'.

Remove any programmes you no longer need using Control Panel > Add/Remove Programmes

Then Start > Accessories > System Tools > Disk Clean Up

The maybe use a registry fixer. (I use CCleaner too - it does the same as Disk Clean Up, but with a few added registry fixes).

Then Start > Accessories > System Tools > Disk Defragmenter

That covers pretty much everything a 'cleaner' programme does, but keeps you in control of your own computer and doesn't run the risk of downloading malware or ads or useless toolbars.

Although the best way, for Windows installations over a year old, is to format and reinstall. Windows is broken and bulky and slows itself down with time. :/

Umm... I hope that helps!