I haven't tried NT4 but I found xp to be very stable compared to other versions of windows (98,ME etc) however, I agree on the insecurity issue. Hell everytime I format my pc and install a fresh copy of windows, I usually create an internet connection right away to download winzip and other such programs, and I always get that blasterworm that gives you the RPC error and forces a shutdown. I can be connected for like 15 seconds and BAM I have it. Yes, there have been patches released to fix this, but with more competition MS might be forced to make their software extra-safe before releasing. I think they work more towards a 'done' version of their software than a 'complete' version.