On Tue, 2008-03-18 at 14:47 -0400, chloe K wrote: > hi Stuart > > thank you so much. you are very helpful > > but someone made this computer to hide something > sysctl -a and /etc/sysctl.conf are not in the system Are you sure? Check if you have /sbin/sysctl. If it's there, you're probably trying to run sysctl as a normal user rather than root. Since /sbin is not on the default PATH, the Shell won't find it. Also, do "rpm --verify procps" (as root) and see what it says. This checks that the procps package which sysctl is part of, is correctly installed. poc