winxp “rundll32.exe” error

Hello sir
I am user of windows XP Prof… OP.But to day i made lot of changes

on ipSecpolocy From Administrator Tools.But i occured sudden prob on my

system that was

“If i want to open any exe file from control panel then it show
error of Windows cannot find rundll32.exe make sure you typed the

name correctly,and then try again.To search for a file click the

start button and click search…. and so on…”

As same i open any installed program from start button then i

occered same error with include of windows can not find path make

sure the path…. and so on… ”

please help me….