Windows 7: Toshiba Satellite S855, trying to install Windows 7

My fiance surprised me with a new laptop today, a Toshiba S855. It came with Windows 8 and I want to use Windows 7 Ultimate 64bit. I finally got it to boot up using the Windows 7 install DVD but now I'm stuck again.
windows cannot be installed to disc 0 partition 1
There are 5 partitions and I get that message with all of them. I tried a Google search but the answers are conflicting. Some people say that deleting the partitions works but others advise against it. I'm not very tech savvy and I don't want to do anything that I'll regret.
Any help would be very much appreciated! I have a picture of my laptop with showing the error but I'm unable to upload it here because I'm on my (Windows 8) phone.

I forgot to mention that it is a S855D-S5120 model. If I am able to install Windows 7, will I need to find new drivers? I googled the model name + Windows 7 drivers and found nothing.

Hi Cam before you go and wipe out Windows 8 from your laptop. You might want to create a Recovery Discs from within Windows 8.

If you want to downgrade to Windows 8 to 7 . Take a look at this tutorial Downgrade Windows 8 to Windows 7

To install Windows 7 you would need a valid Windows 7 key . Hopefully you have that Legit key . The one on the back of the laptop or behind the battery will not work either due to its a Windows 8 Key.

This will help you as well Clean Reinstall - Factory OEM Windows 7

I am not able to locate the model S855D-S5120 on Toshiba's website .

If you would like to Install Windows 7 under UEFI take a look here UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with

If you want to do a clean install take a look here Clean Install Windows 7

This tutorial Secure Boot - Enable or Disable in UEFI

Thank you so much! I'm going to give it a try following the tutorial. I'm sorry for missing that, I guess I didn't look closely enough before I asked my question.

No Problem. If you need any help we are here.

Hum Camx am just wondering maybe an idea to check out your warranty with Toshiba too as they may not be that impressed with you changing the OS. Mind you if you are successful at least you will not have the bloat they throw on them.

I say this as from experience with this brand the repair costs are not cheap!!

Thank you both! I'm in a fortunate position where if I manage to break anything, it can still be exchanged without a hassle. I would really prefer to not break it though lol
I'm making my recovery disc now (having issues with that too but I think I can figure it out) and then I'll go ahead with the Windows 7 install.
But should I be worried about the apparent lack of Windows 7 drivers for this specific model? I'm sorry if that's a dumb question. And thanks again for all the help!

Well at least you have done the right thing Camx - making the recovery disk as it is something one sees all too often in fixes (that I do) but I blame that on the retailers because all they are interested in is the sale. I do set ups for my co workers when they get new machines and so they all get those disks and it saves so much time and hassle when something goes really south.

Nice little machine you have there but from experience with Toshiba's just be careful with handing them as I have had a few in that have had broken power input and USB sockets that are the pits to repair if at all. See - Toshiba Satellite S855-S5254 Overview & User Reviews - Laptops - CNET Reviews This is mainly because Toshiba once a really top brand in my view sadly have dropped the quality for numbers.

Having said that my two Toshibas I have fitted SSD's and more RAM to plus an OEM 7 OS and they perform really well especially without all that bloat.

OEM's vary in whether they will support a Clean Reinstall but they cannot void the hardware warranty - only insist it has the factory install on it to support it or service the warranty.

Then with a Win8 PC you need to disable Secure Boot to either install Windows 7 in UEFI mode as already provided, or choose Legacy BIOS to Bypass UEFI to Install WIn7.

Windows 7 is driver complete so you shouldn't have to provide any drivers after all rounds of Important and Optional Updates are done following the steps in Clean Reinstall - Factory OEM Windows 7. But if so you will most likely be able to use Win8 drivers or Windows 7 drivers will searchable on the web. Let us know if you need any further help.

Downgrade Windows 8 to Windows 7

You need to do all of the step 3 first.


Take a look at this post.
UEFI Bootable USB Flash Drive - Create in Windows - Page 7

Found this on Toshiba Support site.

How to enable CSM for a Toshiba.(Satellite Pro C870, Satellite Pro L830, Satellite Pro C850, Satellite Pro R950, Portege R930, Portege Z930)


Steps to Install Windows 7 on a Windows 8 Unit
Necessary changes in the UEFI Firmware (BIOS) for a successful downgrade from Windows 8 to Windows 7



Toshiba How-To: Resetting your UEFI Bios Firmware on Windows 8 - YouTube
How To: Enter the system BIOS or UEFI in Windows 8 - Toshiba Forums

How to make Toshiba Recovery disks.


Toshiba How-To: Understanding Windows 8 system recovery options - YouTube

http://cdgenp01.csd.toshiba.com/cont...640-SP4015.pdf
Toshiba How-To: Create System Recovery Media on a USB Flash Drive - YouTube

Toshiba Satellite Pro C640/C650 with Windows 8, make recovery disc, page 68

http://cdgenp01.csd.toshiba.com/cont...50_10Apr09.pdf