Mac OS X Tiger, version 10.4.9 as my primary OS Mac OS X Panther, version 10.3.9, on my mom's computer Mac OS 9.2.2, occasionally on my mom's computer Windows XP Pro on my home PC (I hardly use it, but I want to brush up on my Windows, which is why I joined this forum) Windows XP Home on my sister's laptop, who I help with her web design Windows XP Home at school I used to use Windows 95 up until 2001, which we then got a new Gateway Profile 3 with Windows 2000. We upgraded it to XP in about 2004, but I switched to a Mac then on what is now my mom's computer. I vowed to myself when I switched that I would stay current on both platforms, so I would know 99% of all computers I used like the back of my hand, but I didn't really see a need to use Windows anymore. I've decided to brush up on it because I'm now required to use it more often, and I'll be using it a LOT more next year. Never tried Linux, never had any plans to.