I have a Acer Aspire 5536, fairly new i dont have much stuff on here really but when i first bought it watching videos was perfect but now it very jumpy and laggy and drags all the time impossible to watch movies, I was told it may be a trojan or virus, i run multiple scans with mal ware bytes and still its lagging like crazy and when itunes is up its impossible to go on a movie site becuase it just laggs like crazy... What do you think this could be?