I have Win 2k sp3 installed. I want to know weather installing sp4 would improve the performance and stability of my os, or is it not necessary to install it. My sys is a stand-alone pc, not connected to the internet. Any data transfered to my computer is first scanned 4 virii (i hope i got the plural right ) on another computer before I transfer it to my pc. So me think rectifying security flaws in OS not much of a use. What say?