It's always best to do your research before you start any project and this is especially true in IT.
When I started my journey with Ubuntu (Hardy Heron), it was no more than an experiment on a spare PC that I had lying around: over the next couple of years, Ubuntu became my primary operating system for an outlay of less than £100 for a new hard-drive (if you ignore the cost of the PC as a sunk cost) and that's not bad for a for a system that can do everything the competition can, requires a fraction of the disk space of Windows and is significantly more secure into the bargain!
Moreover, one of the great things about Ubuntu is that it will always be free and that includes security updates and OS upgrades. Compare that to Windows: if I wanted to upgrade Windows Vista to Windows 7 (probably not a good idea anyway), I could expect to pay between £70 and £100 for the privilege (based on today's Amazon prices for Home Premium upgrade) and hope that all my existing software would work.
Sadly however, I rarely take my own advice! At the weekend I decided to take a peek at Ubuntu's new release, Lucid Lynx (10.04 LTS) and, in a fit of uncontrollable enthusiasm decided to upgrade!
The short version is that the escapade was a disaster: my graphics card is not supported and I couldn't get the visual effects to work (even in normal mode) so I ended up rebuilding Karmic from the floor up. The good news is that I've rather enjoyed the rebuild and it was great to see how far I've come in open-source computing in a relatively short space of time. More to the point, I would never have been brave enough to even countenance upgrading a Windows machine: so even a failure turned out to be a success!