You're in a tough situation. My uncle and I went through this with my grandfather. We use macs and he uses a PC. Of course, his PC never works and is always unreliable, and he's always coming to us for help, even though I haven't used one for five years, and my uncle has *never* used a PC in his life.
We've told him to switch to a mac, but he's used to some of his software apps and doesn't want to switch or buy new ones. He just wants a working PC, but as we've told him, that simply doesn't exist unless are willing to learn how to maintain PCs, or you have an IT guy on call. The quickest solution is to just get a mac and spend the hours it takes to learn how to do stuff the mac way.
So last year, his PC became unusable, probably just OS rot, and he got a new one, and now he complains about that one too. He'll probably never change.
On the other hand, my wife is now a Mac user and is hooked on iTunes and iPhoto. She had a PC too that didn't work, and was thinking of getting a new one, and I told her that if she did, there was no way that I could or would ever maintain it for her, and to just use my Mac instead whenever she wants.
She complained for a while, asking things like "why doesn't mac have the end key" or "how do I maximize" and I'd help her out, and she picked it all up finally and became less frustrated. But that process took her about 6 months to realize that macs were useable, and then another 6 months to realize they had a lot of great features.
