Dell Latitude D600 Won't Start Up

This problem began just yesterday. I try to start up my computer after it's been turned off/put on standby.... and it just won't start. The power light in the bottom right will turn on for 5 seconds, then shut off and the boot attempt fails. After about 20 attempts, it will finally boot up and work like normal. But then when I shut it down to bring it to work, it did the same thing again today.

 

There are three lights in the bottom right - one is a turn on/off one, one is a plugged in one, and the middle on is an activity one i guess (it flashes a lot when the computer is in use). This light usually turns on at startup - but when the startup will fail it never turns on.

 

Please help! Is this a virus or a hardware problem?

 

thank you so much!
Katie