Acer Aspir 4715z How Bios Password Clear

install Acer e setting management and you install CmosPwd.

Click Start-->Run: type CMD hit Enter on your keyboard. 
b. now us the CD command of Dos to come to d:\cmos\windows. (here is: d: hit enter; cd cmos hit enter; cd windows hit enter).
c. when you are already in d:\cmos\windows in drive D then: type “ioperm.exe –i” hit enter.
d. to start ioperm service: type “net start ioperm” hit enter.
e. ok, type: “Cmospwd_win.exe /k” hit enter, we will see:

1 - Kill cmos
2 - Kill cmos (try to keep date and time)
0 - Abort
Choice :

Type 1 and hit Enter to clear cmos.

f. run the Acer eSettings Management program: start-->program-->Acer Empower Technology-->Acer eSettings Management.

now come to the: Bios Password to see: if you still see password enable, that means we fail but if we see they are Disable so we are done. Remember if we success remove password then we have to create a password for it and then remove it and click Apply to save to cmos memory. This is very important because sometimes we see it Disable but when reboot the computer they are Enable again cuz the password is still in the 

If you reference page 49 and 50 of the Acer Aspire 4715z Service Manual, it explains. You have to use the get at the motherboard and "short" a jumper setting to clear the bios password. It explains there. If you do not want to do that(and most people do not), then you can go to Acer's website and look for a bios update utility. You can flash your bios to same or upgraded version and that should also clear your password.