My computer powers on fine and is functional and i know its working cause i see myself logged on aim yet the computer monitor is blank yet the power is on and computer working fine. I’m wondering is this because there is too much dust on the fan? It takes like 10 or more tries before the computer finally powers on

Windows XP. The computers about 4 years old. We recently moved, and I just plugged it back in to everything. I triple checked all the cords. The monitor works with other computers.
I dusted the computer, unplugged the montior thing and let it run a self test etc. It all works except with my computer. What could be the problem? Pressing buttons, moving the mouse or even opening the CD drive won’t work. :\
Yes, the lights of the computer are still on.

I shut-down my computer, but my monitor power button is still flashing green. When I press on the power button to turn it off, it still blinks green. The only way I can get it to stop is to remove the plug for the surge protector outlet.

What does this mean? Have any of you experienced this?

Thanks so much.

I am not sure what brand monitor it is other than a dell flat screen. I have done everything I know how to do and I am usually pretty computer savvy. It just will NOT POWER OFF unless I turn off my computer CPU and then it powers off and when I turn on it powers on but will not power off when the CPU is still running. What can I do?