I recently got an ASUS K55A series laptop with Windows 8 on it, and have been trying to load Windows 7 on it for days to no avail, and recently I discovered how to get my Windows 7 install DVD to boot from the BIOS, but I deleted all of my Windows 8 system information from both partitions of my HDD and Windows 7 setup says it cannot install on the disc because of a partition format issue. I did not delete the recovery HDD partition for Windows 8, but I can't get the HDD to show up in my boot menu in BIOS, and none of the F keys work to get to recovery mode (only DEL and F2 work to get me into BIOS)
In addition to that, if you do have UEFI enabled and you're trying to use a 32-bit Windows 7 install source it won't work, as UEFI booting is only supported in Win7 64-bit.
For that notebook UEFI booting is optional. So if it's enabled, disable it and try installing Windows again.