Which OS do you use? Windows, Linux, FreeBSD, or which? Why?

my friends and i always use windows xp,windows vista i can't use it,liunx and freebsd i use it,i study this os,i use these os in vmware,liunx is redhat 9.0, freebsd is 4.2

I'm currently using Windows XP and Windows Vista on my desktop and Windows XP on my laptop. Vista is good most of the time, but it can be slower than XP.

Windows only Very user friendly

currently I'm using Windows XP Pro SP2. never tried other OS like Linux before. Will just use the built in OS that comes with the computer hehe.

I use Windows Vista, simply because it is what my brother installed for us, and I never thought of changing. It works well, pretty fast. However, sometimes, it crashes for no reason, and the computer shuts down autimatically if it's left alone for more than an hour, which is annoying to say the least.