Can't get dual boot Windows 7 / Windows 10


  1. Posts : 16
    Windows 10
       #1

    Can't get dual boot Windows 7 / Windows 10


    I'm trying to set up my computer to allow me to dual boot into Windows 7 and Windows 10. I have some critical programs that won't run in windows 10, so I need to keep my windows 7 install available.
    I also decided to buy a SSD to run windows 10 on, so I could get better performance. (Since windows 10 runs like garbage if you don't use one.)
    I just installed my new drive and installed windows 10. All the tutorials I found online showed windows 10 automatically finding the the windows 7 install (as long as you installed it on a separate partition) and it worked without any problems. However when I did it I had no such luck. Looking around, it appears that this automatic magic only works if you install both OS's onto the same physical drive.

    Is this correct? Or is there something I need to tweak, like in my BIOS maybe?
    And moreover, how do I manage to actually set up my system to allow me to boot into windows 7 again?
    I imagine I could change the boot order in the BIOS, but I'd like a more user-friendly system that doesn't require me to pound the del key every time I switch.

    Other info:
    The "system reserved" drive from my windows 7 OS now shows up in my PC as the D drive, and my former C drive as the E. I don't actually see any system reserved drive for the windows 10 install when I check Disc Management.

    Also I'm concerned about screwing up functionality with changing drive letters.
    If this new windows 10 install is on C and window 7 is now E (my D drive is a secondary HDD) then when I run windows 7, wouldn't all the programs I have on there be looking in the wrong location?
    I suppose if I have to, I don't mind if E and C swap letters depending on which OS I boot into. Otherwise I guess I could have the windows 10 installed to the E drive? (I have nothing on here yet so it would be easy for me to reinstall it right now.) But I kind of worry that most new programs would default to installing on the C drive instead of the drive the OS is on. Or is that not really a concern?

    But the System Reserved partition showing up as a user-accessible drive... That bugs the crap out of me, and has me worried something is going to write something to it and ruin it.
      My Computer

  2. MisterEd's Avatar
    Posts : 880
    Windows 10 Pro 64-bit v21H1
       #2

    In the following post I showed how I dual-booted Windows 10 and Windows 7. I used EasyBCD to configure the dual-boot.
    Trying to dual boot Windows 7


    EasyBCD
    EasyBCD - NeoSmart Technologies

    Select "Non-commercial Free"
    Register for free download
      My Computers

  3. AddRAM's Avatar
    Posts : 4,276
    Windows 10 Pro x64 21H1
       #3

    You should have unplugged your W7 drive (the power cable) before you installed W10.

    Your system reserved partition should not have a letter, remove it in Disk Management.

    Whatever Operating System you boot to will be C, don`t change anything, it`s perfectly normal.

    Don`t swap any letters or you`ll mess everything up, just remove the letter from the small System Reserved partition.

    Any games or programs that you installed on W7 will still work fine, from W7.

    Any games or programs that you install W10 will work fine, from W10.

    Your worst mistake was leaving any other drives plugged in when you installed W10.
      My Computers


  4. Posts : 16
    Windows 10
    Thread Starter
       #4

    Okay, I will take a look at that post. Thank you for the link!

    AddRAM said:
    You should have unplugged your W7 drive (the power cable) before you installed W10.
    Well, had there been any results that TOLD me this...

    AddRAM said:
    Don`t swap any letters or you`ll mess everything up, just remove the letter from the small System Reserved partition.
    Okay, how do I remove the drive letter? I've never seen that as an option in Disc Manager.

    I don't have anything installed on this new drive yet (other than windows) so starting over again isn't a huge hassle.

    AddRAM said:
    Whatever Operating System you boot to will be C, don`t change anything, it`s perfectly normal.
    I do believe it is possible to install windows on different drive letter; I've got like a dozen old XP machines I use for retro gaming tournaments, and one of them somehow got Windows installed on E. It seems to work fine. (But then again, I'm not installing a lot of different programs on it, so I wouldn't know if some one random app just doesn't know how to handle this.)
    But I guess that's not the point.
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  5. NavyLCDR's Avatar
    Posts : 16,000
    Windows 10 Pro
       #5

    You only need to run one simple command in a Command Prompt with Admin ("Run as Administrator") assuming that you have done nothing with changing drive letters, hiding partitions, etc. The simple command is:

    Code:
    bcdboot E:\Windows /d /addlast
    Please just run that one simple command, reboot the computer and let us know the results.
      My Computer

  6. AddRAM's Avatar
    Posts : 4,276
    Windows 10 Pro x64 21H1
       #6

    That`s only if you install Windows from Windows.

    Your Thread title is Dual Boot.
      My Computers



  7. Posts : 16
    Windows 10
    Thread Starter
       #7

    Thank you all for your help!
    I removed the drive letter from the system reserved partition (there was an option within the disc manager, I just didn't see it,) and installed EasyBCD. I now get the option to boot to either OS and it looks like the windows 10 boot screen like in all the images I saw earlier.
    Once I was back into Windows 7 I had to change some drive letters around, including removing a drive letter from the system reserved again.
    I haven't booted back into Windows 10 again just yet, but I expect that it should work just fine.

    Side note, I am a little concerned that Windows 7 didn't recognize its own "system reserved" drive when it booted, and I worry that when W10 assigned it a drive letter it also changed something and now W7 doesn't quite know how to handle it the way it is supposed to. It's like W10 touched the baby bird and now the mother doesn't want it.
    Is this something I should be concerned about? Or is this just as fictitious as that "mother won't take it back" nonsense about birds? If the former, then how do I restore it to what it should be?
      My Computer

  8. AddRAM's Avatar
    Posts : 4,276
    Windows 10 Pro x64 21H1
       #8

    I told you not to change any drive letters, and just remove the letters from the system reserved partition.

    Please post a shot of Disk Management from W7 and a shot of Disk Management from W10.
      My Computers


  9. Posts : 16
    Windows 10
    Thread Starter
       #9

    I only changed the drive letter for my secondary drive, which I want to be D on both OS's.

    As I said, everything seems to be working now; I'm just slightly concerned that the "system reserved" isn't being utilized properly since both OS's tried to assign it a drive lettter.

    Here's my current disc managers:


      My Computer


 

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