1. AVG Antivirus http://free.grisoft.com/
I have been using the AVG antivirus solution for over 3 years now, and never had a virus infection shutting my system down, or causing loss of data. With the new version, it has become more user friendly, and can be configured to do automatic downloading. It scans your email for viruses, and has a pretty good heuristic analysis. Once you download, remember to go to the options and set a schedule for downloading updates, or the automatic updating feature wont work.
Runner Up: Avast Antivirus Home Edition
Commercial alternative (CA): Norton Antivirus 2005 $49.95

2. Spybot Search and Destroy http://www.safer-networking.org/en/download/index.html
Your computer may be slowing down because of various programs that are running in it without your permission or knowledge. Some of these may have been installed along with some software that you used. Get rid of all these bugs, and decide which programs need to start when you start windows, by using this software. You can also set the program to monitor changes on your computer, homepage settings etc in real time. Be aware that you need to keep updating this program, just like you would do with an antivirus program.
Runner Up: Ad-Aware
CA: Spyware Doctor: $29.95

3. Spyware Blaster http://www.javacoolsoftware.com/spywareblaster.html
In conjunction with Spybot S&D, this software protects your computer from all the baddies on the net. According to the developer, use it to
- prevent the installation of ActiveX-based spyware, adware, browser hijackers, dialers, and other potentially unwanted software.
- Block spyware/tracking cookies in Internet Explorer and Mozilla/Firefox.
- Restrict the actions of potentially unwanted sites in Internet Explorer.
Spyware Blaster also has to be updated regularly, but does not need to be kept running all the time, unlike antivirus software and Spybot S&D.

4. Zone Alarm Free http://www.zonelabs.com/store/content/company/products/trial_zaFamily/trial
_zaFamily.jsp?lid=home_freedownloads
In these days of ’’always on’’ broadband connections and wire-free computing, not having an efficient firewall installed is an invitation for disaster. A combination of antivirus, anti-spyware and firewall will go a long way in keeping intruders out and is considered essential in every computer these days. Zone Alarm is free for non commercial use, but lacks advanced features such as pop-up blocking, spam blocking, antivirus etc that are available in the Suite version. However, other free software are available which can carry out all these tasks (eg: Yahoo toolbar with anti-spy) and the free version of Zone Alarm will be adequate for all home users.
Runner Up: Sygate Personal Firewall
CA: Zone Alarm Security Suite: $39.95

5. Open Office http://www.openoffice.org
One of the best free Office suites, based on the Star Office suite. Does almost everything that MS Office does, but does not appear to be as slick. Includes counterparts for Word (Writer), Powerpoint (Impress) and Excel (Calc). Also has an HTML editor and a ’’Draw’’ program for creating simple images and graphs. I loved its auto-complete feature which helps you while typing, and the ability to save documents in the PDF format. A more detailed review has already been posted by me on MS (5 best websites...).
Runner Up: Easy Office
CA: MS Office 2003: $499

6. Irfan View http://www.irfanview.com/download_sites.htm
It is one of the best image viewers available in the world today. In addition, it allows some image manipulation, such as cropping, blurring, creating panoramic images etc. It also has a screen capture facility and supports various plugins which transform it into a multimedia player of some repute. A more detailed review has already been done by me in Mouthshut, which you can refer for more details.
CA: ACD See $49.99

7. H-Menu http://home.planet.nl/~vrloohdv/homeEN.htm
H-Menu is a fully configurable launcher,which remains invisible until activated. Activation can be done by taking the mouse cursor to the edge of the screen, when an animated toolbar drops down. The toolbars (upto eight in number) contain all the links that you have saved, and clicking on an icon launches the appropriate program. You can now say goodbye to the START button and have that beautiful picture on your desktop without icons disfiguring it completely. While playing games, you have to remember to inactivate H-Menu by clicking on its tray icon. Otherwise, your game may suddenly disappear and H-Menu make an unwanted appearance, when you take the mouse cursor to the edge of the screen during your game!

8. GIMP http://www.gimp.org/windows/
GIMP is an acronym for GNU Image Manipulation Program. It is a freely distributed program for such tasks as photo retouching, image composition and image authoring and has been called the poor man’s Photoshop. If you already know image manipulation and multimedia editing, you will find this program easy to use, as most of the features are similar to Photoshop’s. However, this is not a program for a beginner, as the help files are rudimentary, and the program differs from Photoshop enough for Photoshop manuals to be useless. Very good for advanced users, as well as professionals with small quantities of work.
Runner Up: PhotoFiltre
CA: Adobe Photoshop $599

9. Leechget http://www.leechget.net/en/
Leechget is a download manager which supports various features such as automatic downloading, resumption of broken downloads, multi-threading, a download timer, automatic hang-up and shutdown and more. You can download complete websites with all images and scripts using this program. A plug in will also allow you to use Leechget with Mozilla or Firefox. It does everything that Getright does, and does not irritate you with a nag screen.
Runner Up: Download Express
CA: Getright $25(also available as a shareware with a nag screen)

10.CutePDF http://www.cutepdf.com/Products/CutePDF/writer.asp
This simple software installs a printer driver, which converts any document that can be printed, into a PDF file. You will need to install Ghostscript (http://www.cs.wisc.edu/~ghost/doc/AFPL/get800.htm)or another PS to PDF converter (http://www.cutepdf.com/download/converter.exe) to make it work. This is a simple solution to creating a PDF file, for those who just want to send a document over the net, or want to post it on a website. Unlike the commercial version from Adobe, it does not allow you to save hyperlinks, and there are some other limitations. But for the casual user, it is more than adequate.
CA: Adobe Acrobat $449