Windows XP is the best operating system I've seen to date. It is rock solid, easy to use, etc. Norton does work on Windows 2K. You do need to update to the proper version. I use Norton Systemworks 2002. I have absolutely no problems with Norton Systemworks. I've used it on all versions of Windows since Windows 95. No problems. 256MB of RAM is still very "light," when you consider all the wonderful Poser stuff out there. I have an Intel Celeron 533mhz computer with 512MB of RAM. Yes, I'd love to have a more powerful computer. I'm basically able to handle anything I get for Poser without resizing any textures. If you want to handle Poser without problems, get Windows XP. Increase your memory up to 512MB at least. You might also want to look at getting a larger hard drive. I devoted a 30GB hard drive to Poser all by itself. That includes all the Poser stuff I download and buy, and all my projects. That was the best decision I've made.