1. Cost -- Linux is free, and that includes all the apps. Microsoft is greedy. Vista Home Premium and Ultimate cost hundreds of dollars, even when upgrading from Windows XP. Moving up to Office 2007 involves handing over another bundle of dollars.
2. Resources -- Even the most lavishly equipped Linux distros demand no more resources than Windows XP. Vista is greedy: a single-user PC operating system that needs 2GB of RAM to run at acceptable speed, and 15GB of hard disk space, is grossly obese.
3. Performance -- Linux worked faster on my Dell Inspiron Core Duo than XP, at least the way XP worked out of the box. After cleaning out the bloatware and trading McAfee's Abrams Tank for the lightweight NOD32, XP and Linux (with Guarddog and Clam-AV) perform at similar speed.
4. No bloatware -- Linux is free from adware, trialware, shovelware, and bloatware. Running Linux is like watching the public TV network.
5. Security -- Last year, 48,000 new virus signatures were documented for Windows, compared to 40 for Linux. Still, most distros come with firewalls and antivirus (AV) software. Programs like Guarddog and Clam-AV are free, of course.
6. Dual booting -- The best Linux distros make dual booting a simple affair, along with the required disk partitioning (so you don't need to buy partitioning software). Windows on my Dell laptop is still intact after installing and uninstalling a dozen distros.
7. Installation -- Anyone who's done it once knows that installing Windows from scratch takes hours or even days by the time you get all your apps up and running. With Linux, it can take as little as half an hour to install the operating system, utilities, and a full set of applications. No registration or activation is required, no paperwork, and no excruciating pack drill.
8. Reinstalling the OS -- You can't just download an updated version of Windows. You have to use the CD that came with your PC and download all the patches Microsoft has issued since the CD was made. With Linux, you simply download the latest version of your distro (no questions asked) and, assuming your data files live in a separate disk partition, there's no need to reinstall them. You only need to re-install the extra programs you added to the ones that came with the distro.
9. Keeping track of software -- Like most Windows users, I have a shelf full of software CDs and keep a little book with serial numbers under my bed in case I have to reinstall the lot. With Linux, there are no serial numbers or passwords to lose or worry about. Not a single one.
10. Updating software -- Linux updates all the software on your system whenever updates are available online, including all applications programs. Microsoft does that for Windows software but you have to update each program you've added from other sources. That's about 60 on each of my PCs. More icing on the Linux cake is that it doesn't ask you to reboot after updates. XP nags you every ten minutes until you curse and reboot your machine. If you choose "custom install" to select only the updates you want, XP hounds you like a mangy neighborhood dog until you give in.
11. More security -- These days, operating systems are less vulnerable than the applications that run on them. Therefore a vital aspect of PC security is keeping your apps up-to-date with the latest security patches. That's hard manual labor in Windows, but with Linux it's automatic.
12. No need to defrag disks -- Linux uses different file systems that don't need defragging. NTFS was going to be replaced in Vista, but Microsoft's new file system didn't make the final cut. Instead, Vista does scheduled disk defragging by default, but the defrag utility is a sad affair.
13. A wealth of built-in utilities -- The utilities supplied with Windows are pretty ordinary on the whole, that's why so many small software firms have made a nice living writing better ones. Linux programs are comparable with the best Windows freeware, from CD burners to photo managers, memory monitors and disk utilities. PDF conversion is built-in, both into OpenOffice Writer and into the DTP application Scribus. All you do is click a button on the task bar.