Dual Boot issues

[Paradox_999]

Hi all,

So I am still running and like Windows 7. I finally decided to give Windows 10 a shot as I want to play some DX12 games that take advantage of my video card. I did something wrong as now I can't seem to get a dual boot setup going.

What I want:
Windows 7 system as default. Windows 10 as optional.

What I need:
Some way to have a choice at boot to select the operating system.

What I did:
I bought bought a new 250gb SSD, plugged it into a Sata port and started Windows 7. In Win7 I started Disk Management and formatted the new SSD, giving it a volume label (Windows 10). Win 7 gave it a drive letter of F.

I rebooted into my motherboard's BIOS and set the boot drive as my DVD drive. The DVD drive with Win 10 disk in it started up and I selected the empty SSD for the Windows 10 install. All went well but I can't get Windows 10 to see the Drive with Windows 7 as a boot option using Windows 10's advanced startup options. It does not give me the option of use another operating system (doesn't see windows 7 as a valid option?) but the drive is visible in explorer.

If I go into my motherboard Bios and select the boot drive as the SSD with the Windows 7 install, Windows 7 starts up, again no option to select 10 (but again, the drive is visible in expolorer.

As an aside, now chkdsk wants to check my drives every time I boot (PITA).

I clearly didn't install Windows 10 in the right way, or did I but I am missing something.

help?

(and many thanks ahead of time)

 

[Billb2]

When you install any OS the install program writes a small piece of code to the first sector (the boot sector) of the drive that is set as the boot drive in the bios. From then on, whenever the computer starts up, that small piece of code is loaded into memory and runs. That code tell the computer where the OS (actually the boot loader) is located, that boot loader then runs and the OS starts up.

When you install another, second, OS it's install program sees the previous install and modifies the boot sector code to indicate that there are two OSs. From then on, whenever the computer starts up an "OS choice screen" is displayed that allows you to choose which of the two OSs to boot up. Also, the two OSs are then aware of each other and the drives will retain the same drive letters is both OSs. The only caveat is that the older OS has to be installed before the newer (Win 7 install can't see a Win 10 boot sector and will overwrite whatever is there).

But when you changed the boot drive befor the second install the install program did not see the other OS and wrote a new boot sector to the (now different) boot drive. So... now you have two different drives, each with a different boot sector code and each code pointing to a different OS, and neither OS is aware that the other exists.

BCDEdit or the easier to use EasyBCD can fix your problem.