OpenOffice
Forget Microsoft Office. What you need is a word processor, not a brand. Save on the money and the pain of cd-keys and other authentication matters by using the open-source suite, Open Office. It can do nearly everything Microsoft Office can, and can even save files in .doc formats.
Avast! Antivirus
Anti-virus software doesn’t have to cost hundreds of dollars. Use a free one like the Avast Antivirushome edition. It also updates for free on a nearly daily basis, keeping you up to date and protected at all times.
Paint.Net
Need to do basic photo editing but can’t afford the crazy prices of Adobe Suite? Try Paint.Net, a lightweight photoshop stand in that can do most basic edits. If its inbuilt tools are not enough, take a look at the user-populated plugin forum.
Firefox or Chrome
Using Internet Explorer you can download additional browsers, Either one of these wildly popular internet browsers will do the trick. Download them for free from either the Mozilla or Chrome site. Just don’t rely on Internet Explorer…
VLC Player
Want to watch that DVD in bed, but don’t have a tv in your bedroom? Install VLC Player on your computer and enjoy movies played through your cpu!
Daemon Tools
With laptops and the like coming thinner and thinner nowadays, it looks like the CD-ROM drive is destined for the rubbish heap. Fortunately, you needn’t have to worry about how you’re going to run the latest software, with the virtual disc emulator, Daemon Tools.
Skype
Chat with your significant others or friends around the world with Skype, a free PC-to-PC Voice Over IP programme. You can also make PC-to-Phone calls at much cheaper rates compared to typical land lines.

CutePDF
Ever wondered how PDFs were created? ‘Print’ yours in style with a nifty PDF creator – it’s very useful, especially for home offices.

Adobe Acrobat Reader
Now what’s the use of creating a PDF file if you can’t open it? Most documents downloaded from online are in PDF format anyway, so make sure you have something that can read them.
7-Zip
Need a zip software but don’t want to pay for it? 7-Zip is open source, and is a great little file compressor.