Dual-boot W7 issues.

Azeriel · 03 Jun 2015

Hello. I decided to dual-boot Windows 7. (I already have Windows 8.1 installed)

I followed a tutorial, and I came all the way to getting the installation started. (I disabled UEFI, disabled fast-boot mode and everything in bios, and I created a new partition on my D: Drive, turned it into F: and selected it for Windows install. I got an error but solved this by unplugging my SSD, and then trying again.)

Now. I was screwing my PC back together when the install completed. I set my timezone, I set my username and I set my password. The PC restarted. After the PC restarted it just said "hit any key to boot from USB" when I hit any key, it started the windows 7 installation again.

I went into my bios and set the HDD I installed W7 on to be 1. on boot list. When I restarted the PC after saving the settings, I just got ""BOOTMGR is missing Press Ctrl Alt Del to restart" I went into the CMD settings from Troubleshoot -> Advanced Options (the pc then restarts and opens command prompt window) and I used the command to check for windows installs. It only shows Windows 8.1 as installed, NOT Windows 7. Now, I can of course still use my Windows 8 as long as I select my SSD as default boot-device, but I cannot find or boot W7 in any way. I can see that my F: drive that I created for W7 has now instead of 35gb free, only 20 something. This means there is something on there, but I have no idea what is happening.

If I try installing W7 again on the same HDD (F:) I just get an error. (If you wanna know the error code, I can try again and type it in).

I am basically lost. I have no idea how to google this problem as it seems pretty big and all I get when I search is Ubuntu and W7. Not W8 and W7. I really hope someone here will be able to help me out, it would be much much appreciated!

gregrocker · 03 Jun 2015

Why is your thread marked Solved? Please change it at top under Thread Tools if you still need help.

If this is a WIndows 8 PC, did you disable Secure Boot? Downgrade Windows 8 to Windows 7

If you disabled UEFI for the WIn7 install then you'll need to set some form of Compatibility Mode in BIOS setup, like CSM or Legacy BIOS so that a UEFI install can run beside a Legacy one if Windows 8 is indeed UEFI.

You should also set the hard drive to boot first in BIOS setup and trigger the flash stick installer using the Boot Menu key so that the stick doesn't autostart the install over again at reboots. If this fails then unplug the stick during the reboot.

If you want to try UEFI install then format the stick as a UEFI Bootable USB Flash Drive - Create in Windows using Option One. Then boot the stick as a UEFI device after setting UEFI enabled in BIOS. You can try this with the Windows 8 drive plugged in to see if the 7 install will configure a Windows Dual Boot menu, or leave 8 unplugged to later add it to Dual Boot using EasyBCD (click Download - no Name or Email required)

Let us know how this goes. If you have problems with the UEFI or CSM related settings in BIOS, report back all the choices. Pictures can help a lot; attach files using paper clip icon in reply box.

Azeriel · 04 Jun 2015

Hey, it's marked as solved because I solved it myself. I deleted the partition I created, unplugged my SSD (where W8 is installed) and installed W7 on my D: Drive without creating any partitions. By doing this it fixed everything and I now get the boot-screen and I can use W7 and W8 perfectly. But thank you for your time to try and help out!

gregrocker said:

Why is your thread marked Solved? Please change it at top under Thread Tools if you still need help.

If this is a WIndows 8 PC, did you disable Secure Boot? Downgrade Windows 8 to Windows 7

If you disabled UEFI for the WIn7 install then you'll need to set some form of Compatibility Mode in BIOS setup, like CSM or Legacy BIOS so that a UEFI install can run beside a Legacy one if Windows 8 is indeed UEFI.

You should also set the hard drive to boot first in BIOS setup and trigger the flash stick installer using the Boot Menu key so that the stick doesn't autostart the install over again at reboots. If this fails then unplug the stick during the reboot.

If you want to try UEFI install then format the stick as a UEFI Bootable USB Flash Drive - Create in Windows using Option One. Then boot the stick as a UEFI device after setting UEFI enabled in BIOS. You can try this with the Windows 8 drive plugged in to see if the 7 install will configure a Windows Dual Boot menu, or leave 8 unplugged to later add it to Dual Boot using EasyBCD (click Download - no Name or Email required)

Let us know how this goes. If you have problems with the UEFI or CSM related settings in BIOS, report back all the choices. Pictures can help a lot; attach files using paper clip icon in reply box.