If you're wondering about Win 7, whether to shell out your money or just stay with XP or Vista, and maybe hearing the stories about installation problems... check out
this comparison of Windows and Ubuntu Linux systems.
You see, if you wait a few days (till October 29) you can download a slick version of Linux, brand new Ubuntu 9.10, for free. In many ways it's superior to Windows.
Installing should be easy, but as with Windows, there can be a few challenges. For this reason I'd suggest getting together with some friends, including a geek or two in there, and do it together. Maybe even look up the Linux Users Group in your city. Make sure you know how to get
access to useful stuff like Skype and video codecs (not in there by default because it's not open source software). And once you've got the hang of it, Linux is actually much, much easier to install and update.
At a glance:
Microsoft: W7 2-3GB, no extra programs to do anything. Susceptible to viruses and malware - pay extra for antivirus & anti-spyware or install free versions.
Ubuntu: 700MB, run from CD or install to disk. Lots of programs to satisfy many users. Highly secure, and free!
Lubuntu: 300MB, run from CD or install to disk. Lots of programs to satisfy many users, an Ubuntu variant with a
lean-coded interface, great for speed and for older computers. Highly secure, and free!
I'll be downloading and trying out Lubuntu when I have time in November. I'm impressed by LXDE (the "desktop" that Lubuntu uses) - it's not quite as pretty now, in its early stages of development, but then I like functional more than pretty.
And note there are plenty of other Linux options out there - in fact I'd recommend you download a couple, burn them to LiveCD, try them on your computer and see which you like best.
Dual boot: If you do need Windows for some reason (specialist software, or advanced photo-editing) you can still install Linux. Install Windows first, back everything up, then insert the Linux LiveCD and follow instructions to set up dual boot. Then you've got Linux for secure web browsing and stability, and Windows whenever you need it.
I've had problems with Linux, as I had with Windows, but by and large I'm happier with Linux, and happy to support something created by a community based on a philosophy of openness.