Windows 7: Dual Boot windows 7 and 8 on new toshiba satellite?

I have a new toshiba satellite p870 that came with windows 8 and I would like to install windows 7 on its second hard drive for compatibility reasons. Every time I try to boot from the windows 7 setup disc it gets stuck on the "starting windows" logo screen and will not proceed. I have tried both booting from the disc and doing a custom install from inside windows 8 with the same result. It was necessary to disable secure boot in the bios in order to get the disc to begin to boot. This computer has 2 hard drives and I am attempting to install windows 7 to a partition on the second drive (the main drive had an error about GPT). I am using a windows 7 professional disc received from microsoft a few years ago to avoid burning a new disc. I have set up dual boot on several other computers but this one is different, Is there anything I can do to get this to work?

You'll need to follow steps here to Downgrade Windows 8 to Windows 7 to turn off Secure Boot and then install Windows 7 in UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with, after wiping target HD with Diskpart Clean Command to clear any formatting.

If problems persist many have had success with these steps to Bypass UEFI to Install WIn7.

You will need a Windows 7 retail Product Key to do this.

Take look at the NOTE at end of this tutorial:
Downgrade Windows 8 to Windows 7


You will need to buy a Windows 7 license,

Now I have a big problem. I got the window 7 disc to load and attempted to install it (the computer would not boot from USB, it says that there is no USB boot option). Windows 7 was unable to create a new system partition so I tried deleting all partitions on the drive (a second blank hard drive). Now the computer won't boot at all even with this hard drive removed, it tries to boot from the ethernet port without a disc, using the install disc I can see that the original partitions are still intact. Beforehand I changed the boot mode to CSM as instructed in one of those tutorials. What happened? This new EFI system is giving me lots of problems.

See whether you can set your BIOS to legacy mode.

Did you try to boot Win8 after you changed the CSM setting? If not, change it back.

It should have been set for both modes UEFI-BIOS to keep Win8 booting and install Windows 7 to an MBR disk normally. If you want to install Windows 7 also in UEFI then keep UEFI setting.

In addition if you enabled Legacy BIOS then UEFI Win8 may not boot.

Make sure the Windows Boot Manager is set first to boot in BIOS setup. If that fails try UEFI HD with Win8.

I'm not sure what to do. I can't get to the bios without going through windows 8 but I cant get windows 8 to boot and the windows 8 disc doesn't have the same recovery options as the actual OS so I can't use it get to bios.

Tap the key given for BIOS setup on first boot screen.

What are the CSM settings choices? If you want to install Windows 7 to an MBR disk normally then you want Dual mode UEFI-BIOS. If you want to install Windows 7 in UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with - Windows 7 Forums choose UEFI all the way.

On a Win8 laptop you only need to turn off Secure Boot to allow Windows 7 install in UEFI mode even in a Dual boot, as shown in Downgrade Windows 8 to Windows 7

If changing the settings back fails reset BIOS to defaults, Save and Exit.

There isn't one on this computer. I don't even see the Toshiba logo before it goes to what its trying to boot from (windows disc or failing to boot from the Ethernet).

Every PC has a BIOS setup key. The key on Toshiba is F2.

How To: Enter the system BIOS or UEFI in Windows 8 - Toshiba Forums

You may need to access Windows 8 Automatic Repair from booted Win8 installer or Repair CD to get the Advanced Options for UEFI as shown in the OEM section.