Hi Guys,
you may try this
Power Drain - if computer has a removable battery take it out and remove the charger.
while power devices are out . hold the power button for 10-15 secs [Just to drain the remaining power inside]
if it has an embedded battery just remove the charger then hold down the "power reset button"
underneath the laptop-may use a pin to hold it down [5-6secs]
Plug the adapter in [do not put back the battery] turn on machine "just after pressing the power button" immediately keep taping F2 to enter BIOS.
once in BIOS press F9 to load defaults [it will not erase anything] press Enter to confirm
then press F10 to save and exit and press Enter again to confirm
Once completed . machine will reboots then will go back to the same page
Black screen with movable cursor [Need to wait for like 2-3 minutes] maximum wait time of 4 minutes DO NOT TURN OFF
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Works for both 7-8 OS and some 8.1 units
Hope it Helps