CMOS battery

open the bottom of the laptop theres 3 bays, one for heatsink one for hard drive and one for memory look for battery remove the connector carefully wait 15min plug again you're done

remove battery
remove power adaptor
remove rams
and any tft monitors connected or any source of power

I found that with the keyboard loose but still connected you can flop it open onto the touch pad access the CMOS battery beneath it (Its the one that looks like a watch battery on steroids possibly shrink wrapped and with a lead to a connector on the mother moard). Disconnect it and power up the note book. don't press any keys at all. set dip switch 4 only to on Carefully (use something plastic and don't touch anything else). most Acer will resume normal windows boot and bypass the BIOS password. Once booted and still powered up reconnect CMOS battery. Leave dip switch 4 set to off. You will be able to restart etc now without being locked out during POST or BIOS by pesky Acer Notebook Manager Supervisor Password.