Different ways to determine CPU speed in Windows XP
You can determine the speed of your CPU using several ways. The first to determine the speed is by viewing the speed of your processor which you can access by going to my computer icon and clicking on it. There you will see whole lot of system properties and the speed of the memory and the processor. If it is small then the CPU speed will be slower, but if it bigger the CPU speed will be faster.
Another method will be by checking the speed of the computer during booting, if the computer takes too long to boot then its CPU speed if definitely slow and vice versa.
Hope this helps.