I cannot start my computer?

Do you use a power bar? Any descent one have a built in breaker. Maybe it got tripped.
If there is a RED led on, it means that the power strip is deffective and need to be replaced.

Unplug any additional devices and flick it OFF then ON again.

As Dave said, your power supply may be deffective. Replacing it is a 10 minutes job, and only need a regular philips screw driver.

Electro
February 2012

Take it to a local computer shop and let them have a look at it, could be a power supply problem, cheap to fix.

Dave
February 2012