I don't know what defragging has to do with any of this.
Just burn a copy of the Ultimate Boot CD, pop it in your computer, press enter when it says to, go to hard disk diagnostics, and start the IBM utility. All the instructions are on your computer screen - it really couldn't be easier. You don't need windows to function for the diagnostic to work.
Don't put all your chips on chkdsk. It's skipped over errors the UBCD has found in the past.