I am running Vista Home Premium on a HP Pavilion a6030n. Lately when I want to use the computer after some period of time(typically first thing in the morning), I find the machine will not be on. The fan is running but I can't turn on the machine. I normally leave it on. I have DSL. The only way I have found to start it up is to unplug it and then plug it back in. Any ideas?

   It sounds to me that it is not completely off.  When you want to turn it off after it was supposedly shut down, have you tried holding in the power button for 5 seconds?  If that works to turn the computer off, your computer was sleeping or hibernating.

I don't turn the computer off. I just diconnect from the internet. The computer somehow turns itself off (or partially off).

   Yes, I understand that.  When it is partially off, try holding the power button (the on/off button) in for at least 5 seconds and see if it does anything.  If it does, your computer was either hibernating or sleeping.

This happened to me for a while. I found the culprit to be "Power Options" in the "Control Panel" .  Sorry, I don't recall what I had to do, but it really can be fixed frim there. Just read EVERYTHING in close detail, and think about it's effects.