My computer turns on but when I go to turn it on
a screen pops up saying
"Alert! Chipset heat sink not detected. System halted!"

I've never had this problem before o_O
Anyone know what might've caused this and how I can get it fixed?
Thanks in advance.

The cpu fan might not be seated correctly or not working. Take the computer case cover off and then turn on the computer. Check to see if the fan is spinning when the computer is on.