On ACER ASPIRE E1-510 laptop with factory bios you cannot install Windows 7, only Windows 8 or 10.
For installing windows 7 to change boot option to legacy you need to flash bios (update) and the legacy will appear down to uefi option.
To do this make a bootable stick and to put all need it files on it.
To boot from usb stick you need to disable secure boot.
To disable secure boot you need to :
– Set Supervisor Password and press Enter.
– Create a password and press Enter. Retype the password to confirm and press Enter again.
– Use the right arrow key to select Boot.
– Press the down arrow key to select Secure Boot and press Enter.
– With the arrow key, highlight Disabled and press Enter.
– Press the F10 key and select Yes to save the changes
– remove Supervisor Password and press Enter
– Press the F10 key and select Yes to save the changes
Then follow the instructions from the link bellow (you have a doc file inside) and all the files need it to do the usb stick .
Download ACER ASPIRE E1-510 Update FLASH BIOS laptop not supported install windows 7
Thanks to this guy I was able to Install Windows 7 on ACER ASPIRE E1-510 !