I purchased my computer , (Toshiba Satellite L505 64 bit system ) two years ago , and I have been told they are good for approximately 50,000 hours before trouble may start . First is there any truth to this ? Secondly , is there a way I can check the number of hours on my computer .? I have Chrome as a browser . I use " CCleaner ", and " Defraggler " on a daily basis and have Kaspersky virus protection. Thanks to all that helped me with my previous question !!