Web searches show that F2 is the key to enter BIOS on Acer Aspire One and it was working fine when my system had windows 8. When I upgraded to Windows 10 recently, I see that F2 is not working. I tried power-off and power-on N times with F2 pressed, without success. It was working about 2 years ago, when I had Windows 8.
After update to Windows 10, login screen appears within about 4-8 seconds of power-on.
More-over, the first image on power-on is "Acer logo with windows circle of moving dots", which seems to indicate that windows 10 is already in control, which is probably why F2 (or ALT F10) will not enter BIOS.
Is there any way (control panel setting or freeware tool) which, when executed from window 10, can restore access to UEFI BIOS ?