Windows 8 and 8.1 Forums


Satellite L850 & Win 8 UEFi: How dual boot UEFI win 7 ?

  1. #1


    Posts : 6
    windows 8.1

    Satellite L850 & Win 8 UEFi: How dual boot UEFI win 7 ?


    Hello to the forum. Thanks for the welcome. And thanks for pointing me in this subforum.

    I have a notebook toshiba satellite L850-1HU with UEFI

    Default is win 8 os, recently upgraded to 8.1.

    Now I need to win 7.

    I have a professional license N sp1 x64 and then supports UEFI

    Is possible to combine the systems in dual boot and both in UEFI mode?

    I see from your guides that for installation the UEFI is necessary partition in a certain way.
    What should I do if I want to leave intact the UEFI partition of win 8 (5 partition)? I just make only space for win7(1 partition) that will use the same 4 partition UEFI of win 8 or i make other 5 partition???
    And which of the two systems will handle the boot? I can decide I?

    and the warranty? restores factory work?

    If I change hdd, and install win 7, when I put the old hdd, it works as before removing it?

    Sorry for the confusion! I hope you manage to understand me and help!

    Ciao forum! E grazie! Saluti dall'Italia!

      My System SpecsSystem Spec

  2. #2


    Posts : 376
    W8.1, W7


    If I change hdd, and install win 7, when I put the old hdd, it works as before removing it?
    Yes. This is how I do any OS tests\'dual boot'\experiments etc with zero chance of damage to the original boot OS\hd. Am keeping a bunch of old HD's for the purpose. The downside is the slight risk for some mechanic\connection problems, just be careful, remember to power down! So if you don't find it troublesome to switch HD's, IMO go ahead and try that route.
      My System SpecsSystem Spec

  3. #3


    Posts : 6
    windows 8.1


    This invalidates the warranty?
      My System SpecsSystem Spec

  4. #4


    Posts : 376
    W8.1, W7


    ^^^ No, unless you break something. Warranty allows for normal upgrading and changes like SSD, MSATA, HD, xtra ram (that's why laptops got covers\slots\easy access to those parts) but any errors done in the process, for example bending contacts, short-circuiting something etc would be ...'very difficult' to claim on any warranty. So just proceed with care & awareness, plan what's to be done, and it'll be fine.
      My System SpecsSystem Spec

  5. #5


    Posts : 6
    windows 8.1


    I have done these operations in the past. I'm practical. So UEFI BIOS does not notice the change? Can I keep it active?
      My System SpecsSystem Spec

  6. #6


    Posts : 376
    W8.1, W7


    How I do it: to get it to recognize the new OS installation media (USB) etc: disable Secure Boot, boot mode: CSM. To again use the UEFI OS\HD, these settings needs be reverted.

    Of course all this not very practical if one is to often change between different OS\HD. I use it for testing purposes, with the goal being able to do any experiment\testing while keeping my original OS\HD 100% untouched.

    Attachment, my Tosh 850, new HD fitted, boot > USB W7 install (& W8 UEFI HD with all my files safely out of the way :O)
    Attached Thumbnails Attached Thumbnails t850.jpg  
      My System SpecsSystem Spec

  7. #7


    Posts : 5,592
    ME, XP,Vista,Win7,Win8,Win8.1


    Now I need to win 7.

    I have a professional license N sp1 x64 and then supports UEFI

    Is possible to combine the systems in dual boot and both in UEFI mode?

    YES & NO, down to your UEFI/BIOS firmware setting.

    As this is a OEM manufacturer's PC with Pre-installed Windows 8.

    1) Downgrade to Windows 7.
    Downgrade Windows 8 to Windows 7
    Warning you must have the UEFI/BIOS firmware setting in Step Three set.

    Make sure you read the NOTE at Step three.

    2) If Using a USB Pen drive on a PC with a UEFI BIOS.
    USB Pen drive need to be formatted to FAT32 as in
    UEFI Bootable USB Flash Drive - Create in Windows
    Take note of Step 11 for Windows 7.
    Also you will need to use a USB 2.0 port, as there are no USB 3.0 drivers in Windows 7.
      My System SpecsSystem Spec

  8. #8


    Posts : 5,592
    ME, XP,Vista,Win7,Win8,Win8.1


    From 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)

    Quote Originally Posted by Toshiba
    To downgrade from a installed Windows 8 OS to a Windows 7 OS, using a Windows 7 recovery media, follow these steps:

    1) Boot unit and press F2 to get into BIOS

    2) Go to "Security" tab and disable "Safe Boot"

    3) Go to "Advanced" tab, select "System Configuration" then change boot mode from "UEFI" to "CSM"

    4) Press F10 to save changes and exit.

    5) Boot unit from recovery media (Press F12 on bootup to boot from USB or DVD media)
      My System SpecsSystem Spec

  9. #9


    Posts : 6
    windows 8.1


    So I have to necessarily lose the current configuration of win 8?


    Downgrade oem win 8 to win 7 and after partitioning out and install in 8: in a nutshell this is what I need to do?
      My System SpecsSystem Spec

  10. #10


    Posts : 5,592
    ME, XP,Vista,Win7,Win8,Win8.1


    Quote Originally Posted by ziofrank83 View Post
    So I have to necessarily lose the current configuration of win 8?


    Downgrade oem win 8 to win 7 and after partitioning out and install in 8: in a nutshell this is what I need to do?
    Base YES. Both Windows 7 x64 & Windows 8/8.1 x64 will need be installed in LEGACY mode.
      My System SpecsSystem Spec

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