The Acer Aspire uses an updated version of the BIOS called the Unified Extensible Firmware Interface. You can change the UEFI settings using the advanced options of the update and recovery function in Windows.
Swipe in from the right to open the Windows Charms and choose the gear-shaped Settings icon.
Select Update and Recovery.
Choose Recovery from the left column and select Restart Now under the Advanced Startup options.
Choose Advanced Options.
Choose UEFI Firmware Settings.
If you don't have the UEFI Firmware Settings option on your Acer computer or if you use Windows 7, power off your computer and then power it back on. When the first logo screen appears, press F2 -- or Del on an Acer desktop -- to access the UEFI Firmware settings.