I'm using the Google Chrome Browser and amy starting Dislike as I was using Firefox previously.. But after following the process to Defrag my Computer and after coming to the last stage , after clicking to Defrag my Computer freezes.. I thought of going for a Restore Point but I can't seem to get anywhere without some sort of Pop Up preventing me from doing so... Help Thanks

Try a different defrag application.
I find Auslogic very good and free to boot.
Available here: Download Auslogics Disk Defrag Free (http://www.auslogics.com/en/software/disk-defrag/download/)