What's that? Linux is much too complicated and techie for someone who might have trouble navigating Outlook Express? Sorry, but that's not been the case for years. Take a look at the new Ubuntu 9.10, and you'll see what I mean.
Besides, think about it. If your older relatives are like mine, they use the desktop for e-mail and the Internet, and that's about it. Firefox, with GMail for e-mail, looks and works the same on both Linux and Windows.
Depending on your Linux distribution, you may want to add a few programs to their desktop to give them all full multimedia functionality, like Adobe Flash for Flash media, and VLC Media Player to play DVDs. After that, you're done, and they're good to go.
If you're not to sure about how to install Linux yourself, you can just buy a Linux PC from Dell, which includes most of the multimedia extras, or one from other reputable vendors like System76. No fuss, no muss, and it usually costs a bit less than the same system with Windows.
In addition, with Windows, you must constantly be patching and re-patching it to keep it even halfway safe. If your older relatives are like mine, they're more likely to click on a Hallmark malware e-card than they are to OK an upgrade.
With Linux, it's helpful if they can keep it up-to-date on their own, but it doesn't really matter if they don't. Not only is Linux simply more secure than Windows, the simple fact is that 99.9999% of all attacks are aimed at Windows, not Linux.
Sure, if desktop Linux got wildly popular, crackers would start working on trying to break Linux. But that's neither here nor there. Today, whether you believe Linux is theoretically more secure or not, practically speaking, it is far more secure than Windows.
And thinking of practical, once Grandpa has a Linux desktop, you'll be able to spend your weekend with him watching football instead of updating his AVG or cleaning out malware. I don't know about you, but I know which way I prefer to spend my weekends!