When I press the Log On button firstly in the start of the window it shows: (The system has detected that a cooling fan not operating correctly. Continued operation is not recommended and may cause unpredictable behavior that could result in random shutdown, data loss or possible system damage. The system will shutdown in 15 seconds. To prevent shutdown and continue operation, press the enter key now. System Fan(80B) ENTER: Continue startup For more Information please visit:www.hp.com/go/techcenter/startup)
The fan needs to be cleaned or replaced. If you are lucky you can just blow it out with compressed air. Stick a paperclip in there to keep the blades from spinning out of control and burning up the bearings. Blow it out, do a hard reset. Remove battery and AC power, hold down power button 20 seconds, plug in AC...boot to BIOS (F10) and exit BIOS restoring to defaults. If lucky, this clears the error. If not we need to discuss replacing the fan.