As a frequent downloads reviewer for PC World, I look at lots of downloadable software every year--more apps than I care to count. As a result, each week, I encounter and test-drive the great, the not-so-great, and the feeble.

Every once in a while, a piece of software so clearly outclasses its peers that it deserves special commendation. For this article, I've assembled my 15 favorite dowloads of 2007, selected from a wide range of categories--everything from antivirus and security tools to system tweakers, from media managers to system speedups.

Among them you'll probably find some old favorites, but also plenty of unfamiliar apps that you'll grow to love.

Do you really know what's running right now on your PC? In all likelihood the answer is no. Dozens of processes or services may run in the background without your being aware of it. And though it can show you what's running, Windows' Task Manager is a poor tool for diggng deeper than that.

Process Explorer (a free download) provides exceptionally detailed information about every process and service, as well as identifying any applications associated with them. In Task Manager, you have no idea what each process and service do. But because Process Explorer often shows applications associated with each process and service, you'll be able to tell whether shutting them down is safe. The tool can also uncover clues indicating that a service or process may be spyware or malware.

Download  Process Explorer | Price: Free

These days, most antivirus programs come as part of an expensive, bloated, RAM-hungry suite that sucks up system resources, slows your system to a crawl, and requires you to pay for a new subscription every year. If you're tired of paying through the nose for antivirus protection, and want a slim, svelte anti-virus tool that does everything that high-price software does, get Avast Anti-Virus Home Edition. It has everything you need in an antivirus tool--notably live protection to ensure that you don't get infected in the first place. It also protects against instant messenger viruses, e-mail- and Web-mail-borne viruses, and viruses spread through peer-to-peer file sharing programs. It also scans your system for viruses, and eliminates any it finds.

Avast Anti-Virus Home Edition is free and extremely customizable: You can change the level of protection that any of its individual shields provides from normal to high, or create your own customized rules. So ask yourself, do you really need your current, high-priced suite?

Download Avast! Virus Home Edition | Price: Free

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