Acer Aspire ES 14 - Changing to Windows 7

34 - Changing your Windows version
3. Select Windows 8.1, and then click OK and follow the instructions.
Windows will restart, replace Windows 7 with Windows 8.1, and then
start the Windows 8.1 setup process.
Changing to Windows 7
Start Windows 8.1; from Start, type ‘recovery’ to open Acer Recovery
Management.
1. Select Restore Factory Settings.
Note
After configuring Windows 8.1, enter the BIOS (press <F2> when starting
your computer) enter the Boot menu and change the Boot Mode to UEFI.
See Changing BIOS settings on page 35.
Note
To change back to Windows 7, you must change Boot Mode back to Legacy
BIOS. Windows 7 will not start if the BIOS Mode is set to UEFI.
See Changing BIOS settings on page 35