When my daughter turns her computer on it says the cpu fan is not running and shuts down. The fan is definitely running but it won't go past that screen. Anyone know if I can bypass this safety feature so I can figure out why it thinks the fan isn't working?

Edit:
I got her computer and brought it home. I bypassed the shutdown by hitting F2 and everything seems to be fine now. Shut it down and restarted with no problems several times. She had some AVG antivirus trial thing on so I removed it. Downloaded Firefox with Noscript and adblocker and once again told her to not use IE.

Should I worry about the aforementioned problem though? I don't want her computer to overheat or something.

The fan is not connected to the proper header on the motherboard most likely.