i have inspiron 14r with i3 processor but somedays before it started showing 100% cpu usage for no reason.... i thought it might be virus but norton  kaspesky couldn't find any...... even at times it shut down automatically whie using vlc or explorer or anything which i use normally.....some said about cpu temp.....which maybe the reason of this problem...but i checked the temp.... too at that time when usage was 100 .....it was around 47 at that time......when it shuts down it doesn't open for sometime ...when i press the power button it just blinks then turn of.......then after a while it blinks for longer time when i turn it on again .....doing this for around 10-15 min  after then it starts ormally but then again after a 10-15 min only again cpu usage becomes 100 ad then automatic shut dow.....aslo i have tried using task bar for ending processes and msconfig way...one of which was useful.....please help me