WinUtilities Free Edition is an unusually comprehensive suite for cleaning, repairing and optimising your PC.
It includes all the tools you'd expect to find in this kind of package. So there are modules to find and delete junk files, clean your Registry, remove unwanted startup programs, and locate duplicate files that could be wasting your hard drive space, for instance. One or two of these are weak (the program found very few files to delete on our test PC), but most are effective and easy-to-use.
But there are also plenty of surprises. Like a defrag tool that doesn't just reproduce the standard Windows module, but also adds a host of configuration options: you can move files to the end of the disk, or sort files by name, size, or according to their last access, change or creation time, so there's a good chance you'll find a strategy that works for you.
The suite includes some interesting security options. The Document Protector module allows you to password-protect any confidential files or documents to prevent others from accessing them, for example. While the EXE Protector applies a similar principle to your chosen application executable files, so they can't be run until the correct password has been entered.
And there are a host of other useful tools here, including modules to locate and fix broken shortcuts; defragment, back up and restore your Registry; undelete files, and clear your browser and application histories.
Powerful though this is, the authors also produce a Pro version of WinUtilities that does more, providing extra system optimisation features, additional automation possibilities (so you can schedule particular modules to run whenever you like), and can be used commercially (the free version is for personal use only). Prices start at $49.99 and you can find out more at the YL Computing site.