I was having problem with my computer slowing down and jerky mouse. Someone said to defrag my hard drive. Does this usually take over a 1 1/2 hour ad still not done. It would say "reading drive" go to 10% wait about 10 sec and then either go to defrag to about 61% and start over or say something like "restarting content drive." It was like it was stuck in a loop or something and now the computer is twice as slow as before the defrag.I haven't done anything recently except change my AV program to "files and programs only." Someone said that also might be giving me trouble. Any suggestions?