I got my HP laptop in 2009. It's had its troubles on and off since. But lately I've noticed this happening.....

I'll turn on my laptop and the screen will be black for about 5-15 seconds if not a little longer then it would boot up as usual and log onto my desktop and I can use it freely.

But why is this happening is my laptop going to die? How do I know if a laptop is about to die anyway? Please help!