My Laptop has become slow recently.

When I click on 'My Computer' and click on 'Properties', under 'Computer' it is displayed:
Genuine Intel (R) CPU
T2400@1.83 GHz
987 MHz, 504 MB of RAM
Physical Address Extension

What I am concerned about is this '987 MHz'; should it not be 1.83 GHz ? If you agree, kindly advise what I can do about it.
I have a DELL laptop with Windows XP Home.

is it slow when using mains?

does it have a power saving mode?

Ok here are some potential reasons why you laptops could be slow don't worry about right clicking and choosing properties on my computer. Yes those numbers mean a lot, but if you'r computer just recently started slowing down since you've hade it. The numbers won't be the problem. OK Have you done any anti- virus / spyware scans lately? Have you downloaded or change any settings lately? Did you install service pack 2 lately? If you have done any of these things let me know and maybe i can help.

Michael Knowles