If you're sick of using Windows and looking to try something different, consider Ubuntu Linux Netbook Edition 10.04 (aka Lucid Lynx).
The folks over at Desktop Linux Review has posted a screen-by-screen introduction to the Netbook edition of Ubuntu. It has an alternative interface to the standard desktop edition of Ubuntu, specially optimized for the netbook. If you're not happy with that, and prefer the standard desktop interface, you can toggle between the two, which is a nice touch.
The Gwibber social media client is bundled in, which is a good thing since the netbook is more about communication and web than desktop apps. There's also the Ubuntu One Music Store bundled into Rhythmbox which lets you buy music online, ala iTunes.
All in all, a nice viable alternative to Microsoft Windows. Check it out.
Source: Desktop Linux Review - Ubuntu Netbook Edition 10.04
