BigFix on my parents PC is recomending that the PC should Defragment the disk after 180 days. My parents only use the PC to surf the web. Sometimes their PC is sluggish, but that is only when the anti virus scanner is on. There is no spyware/adware or viruses on the PC. Should I Defrag the disk ? If so, how do I do it ? I read somewhere you should run "Scan Disk", but I cant remember if you run ScanDisk before or after you Defrag the disk. What should I do ? Will the PC run faster if I defrag ?