Saving Money on Software: Open Source
Linux is an open-source operating system. If you are growing tired of paying Microsoft to develop buggy, insecure, and non-conforming software, try one of the many distributions of the linux operating system. I prefer the "Ubuntu" distribution, which is available as a "live CD" - in other words, you can put the CD in your Windows machine, reboot, and try out Ubuntu, without changing anything on your computer. (You can download the CD image from the above location.)
Compared to Windows, Linux offers greater security, more applications, more power, and a more flexible user interface. According to Dr. Nic Peeling and Dr Julian Satchell's Analysis of the Impact of Open Source Software, "There are about 60,000 viruses known for Windows, 40 or so for the Macintosh, about 5 for commercial Unix versions, and perhaps 40 for Linux. Most of the Windows viruses are not important, but many hundreds have caused widespread damage. Two or three of the Macintosh viruses were widespread enough to be of importance. None of the Unix or Linux viruses became widespread - most were confined to the laboratory."
Popular (and free) applications include an office suite (Open Office word processor, spreadsheet, presentation tool, and database manager, all of which can read and write not only Microsoft formats, but many others), image editors, AIM and bit torrent clients, web authoring tools, audio/visual support, compilers, programming environments, games... and of course a number of chemistry applications. The live CD includes a large number of common applications, and installing new ones can be accomplished with a single click or one command line. Most hardware is supported, and usually without the need of any special driver disk or download.
If you have tried Linux in the past and found it too complicated, try again. The past few years have seen a remarkable improvement in the user friendliness of many popular distributions.