Windows 10 2 Disks, 2 Systems

Charles Hohenberg

New Member
Joined
May 4, 2015
I have 2 SSDs with Windows 8.1 on one. I unplugged this disk and installed Windows 10 on the other SSD. I wanted to plug both in and select the boot disk in Bios so I could boot either windows 8.1 or Windows 10. It works great MOST OF THE TIME. However, I occasionally get the message "no valid operating system found insert valid medium", or something similar, when I try to boot to one of the two systems. It appears that the windows that was up and running wrote something onto the boot sector of the other disk with the other windows system on it. There is apparently no recovery that I know of, just have to reinstall the system. What a pain. Apparently, one system will write on the boot record of the other system disk and corrupt it. UI now keep only one SSD plugged in at a time. Does anyonje know a solution to this?
 
Last edited:
I unplugged this disk and installed Windows 10 on the other SSD
This method is known as multi booting (because of using more than 1 HDD)....but the key to remember is when doing so, you have to unplug the data and power cable to the HDD with the original OS. If not you will receive this type of message....
 
I like to call it parallel booting and it is the only way I can see it working. Are you running UEFI for a configuration?

But a Question, I suppose. Did the Windows 10 install have some type of prior install, such as an image from the 8.1 install?

Also, does it make a difference which one you are booting to or were in on the previous session?

The drives really not show up in the boot options unless they are bootable but if you are running Legacy this may not be the case.

I don't put much out of the realm of possibilities, especially since I found out yesterday a UEFI install of Windows 7 and Windows 10 cannot work as a Boot Menu situation, but need the parallel boot..

Edit: You may want to try turning off Fast Startup for testing.
 
Last edited:
I like to call it parallel booting and it is the only way I can see it working. Are you running UEFI for a configuration?

But a Question, I suppose. Did the Windows 10 install have some type of prior install, such as an image from the 8.1 install?

Also, does it make a difference which one you are booting to or were in on the previous session?

The drives really not show up in the boot options unless they are bootable but if you are running Legacy this may not be the case.

I don't put much out of the realm of possibilities, especially since I found out yesterday a UEFI install of Windows 7 and Windows 10 cannot work as a Boot Menu situation, but need the parallel boot..

Edit: You may want to try turning off Fast Startup for testing.
I had a freshly installed Windows 8.1 system on one drive. I unplugged that drive and did a fresh install of Windows 10 on a separate drive. I select which system I want to boot up by selecting the boot drive in the bios. Most of the time everything is fine but maybe one time in 10 I will get the message "no valid operating system is found" when I try to boot one or the other meaning, I think, a corrupted boot block. Why one system writes on the boot block of another disk I do not know. Any way to protect the boot block of the dormant system? Now I unplug the drive I'm not using but that is a real pain.
 
Charles, repeating your original post and not answering questions will not get us much progress. Had you answered the questions, I might have mentioned when you run UEFI, that firmware could be involved.

I have not run an SSD with Windows 10, but I have run your same configuration with Windows 7 and Windows 8.1 without problems. In the past, there have been some SSDs that needed firmware updates, but that has been some time ago.

If you are wanting to get one drive bootable again, as bassfisher mentions, disconnect the other drive and try doing a Startup Repair on the misbehaving drive.

I cannot address your concern about one OS writing to the other drives boot partition, since I have not seen that. If you think that is happening, start watching the system to see if you can discover something which might allow others to duplicate your situation.
 
Charles, repeating your original post and not answering questions will not get us much progress. Had you answered the questions, I might have mentioned when you run UEFI, that firmware could be involved.

I have not run an SSD with Windows 10, but I have run your same configuration with Windows 7 and Windows 8.1 without problems. In the past, there have been some SSDs that needed firmware updates, but that has been some time ago.

If you are wanting to get one drive bootable again, as bassfisher mentions, disconnect the other drive and try doing a Startup Repair on the misbehaving drive.

I cannot address your concern about one OS writing to the other drives boot partition, since I have not seen that. If you think that is happening, start watching the system to see if you can discover something which might allow others to duplicate your situation.

Yes, I change the devices in the EFI. I do not know how to change the boot device without going into EFI Bios, which is what I do to select the boot device and thus the operating system I'm booting into. Sorry I did not make that clear from the outset but that's the only way I know of to select the boot devices and boot order. Thanks for the reply. Hopefully, I can solve this before I again connect both SSDs at the same time!
 
I go through the bios also to change boot devices. I use the F8 Boot Menu option and set one or the other. If I want one drive to stay as primary, I will change it in the boot priority setting so it always boots unless selected otherwise. But this is not really relevant to the problem you describe.

Some systems have an F key option to open a Boot Device Menu, but in many cases, the systems are so fast it is hard to get that menu to open.
 
Depending on mobo manufacturer......the "boot device menu" is either F8 (Asus) and F12 (Gigabyte).....for me I use the F12 key. I tap the F12 key just like I would the delete key, right after the post beep and in 2 seconds up pops the boot device menu. This bypasses entering in the BIOS.....much much easier and safer.

Charles; go back into your BIOS and use the default settings, save and exit....let system boot up fully just to make sure it's fully functional, shut down reattach secondary HDD with 2nd OS and power up and use either the F8 or F12 key to get into the boot device menu.

Youtube will have videos on the subject matter to follow along so you can get a visual of the process.
 
Depending on mobo manufacturer......the "boot device menu" is either F8 (Asus) and F12 (Gigabyte).....for me I use the F12 key. I tap the F12 key just like I would the delete key, right after the post beep and in 2 seconds up pops the boot device menu. This bypasses entering in the BIOS.....much much easier and safer.

Charles; go back into your BIOS and use the default settings, save and exit....let system boot up fully just to make sure it's fully functional, shut down reattach secondary HDD with 2nd OS and power up and use either the F8 or F12 key to get into the boot device menu.

Youtube will have videos on the subject matter to follow along so you can get a visual of the process.

This I have done. What I fear is that, while the boot block is protected on the system disk (the one booted from), the boot block on the other disk (with the 2rd system) may just appear as a regular partition and may be written into as the operating system maintains efficient disk space (by consolidating fragments, etc.). Maybe I could prevent this by some king of "write protection" on the dormant boot block.

It is difficult to immediately assess the result of changes since the problem occurs infrequently but, when it does, it is a disaster.
 
When you refer to systems, such as 2nd system, are you referring to the Other system or a specific system, such as Windows 10 vs. Windows 8? Since I still do not know what type of configuration you are running, it is hard to even guess what might be happening..

If you think Windows 10 is causing the problem, I could try installing it on a SSD I have to test... But as I mentioned, a Windows 7 and 8.1 system has worked fine as UEFI except for the occasional Chkdsk which will sometimes show up if I am moving drives around.

Any chance of getting a Disk Management picture you can attach using the Upload a file button if you are using IE? It appears Edge will not allow me to upload a file.
 
When you refer to systems, such as 2nd system, are you referring to the Other system or a specific system, such as Windows 10 vs. Windows 8? Since I still do not know what type of configuration you are running, it is hard to even guess what might be happening..

If you think Windows 10 is causing the problem, I could try installing it on a SSD I have to test... But as I mentioned, a Windows 7 and 8.1 system has worked fine as UEFI except for the occasional Chkdsk which will sometimes show up if I am moving drives around.

Any chance of getting a Disk Management picture you can attach using the Upload a file button if you are using IE? It appears Edge will not allow me to upload a file.
I don't know how to take a picture of the disk management screen
 
Here (I think) is a picture of the Dist Management screen. After everyone feeling fairly certain there is no problem is have both system disks attached at the same time, I now have both. Disk C is Windows 8.1 (on a 256gb SSD) and Disk D is Windows 10 (120gb SSD, build 10074). I also have a 1Tb conventional HDD Disk F. I will run with both attached for a while and hope both stay pristine! Thanks guys, and let me know any thoughts.
 

Attachments

  • 20150507_115449.jpg
    20150507_115449.jpg
    2.7 MB · Views: 201
Open Disk Management, diskmgmt.msc, and take a picture using the snipping tool. Or you can use the Winkey+X menu, or right click in the lower left corner of the desktop and select Disk Management.
 
Here (I think) is a picture of the Dist Management screen. After everyone feeling fairly certain there is no problem is have both system disks attached at the same time, I now have both. Disk C is Windows 8.1 (on a 256gb SSD) and Disk D is Windows 10 (120gb SSD, build 10074). I also have a 1Tb conventional HDD Disk F. I will run with both attached for a while and hope both stay pristine! Thanks guys, and let me know any thoughts.
Well, it had been a few days since I booted Windows 8.1 and there were 3 updates to apply, after which a restart. During the restart I got the message "scanning and repairing disk (D:):", the one with Windows 10 on it. Here we go again, another weeks work ahead of me! I'm still updating Windows 8.1, after which I will try to boot Windows 10 (by changing the boot device to that disk). We will see ... Any suggestions?
 
Open Disk Management, diskmgmt.msc, and take a picture using the snipping tool. Or you can use the Winkey+X menu, or right click in the lower left corner of the desktop and select Disk Management.
I took a photo of it. Click on the file to view it. Thanks, and see the note above!
 
You have a Legacy install, so any mentions about UEFI are not relevant.

You have two active partitions, so the boot files may be in separate partitions, or they may be in the one currently designated as System. But I have not seen a Legacy install have boot problems. Do you know why you have two active partitions?
 
You have a Legacy install, so any mentions about UEFI are not relevant.

You have two active partitions, so the boot files may be in separate partitions, or they may be in the one currently designated as System. But I have not seen a Legacy install have boot problems. Do you know why you have two active partitions?
 

Attachments

  • 20150507_124934.jpg
    20150507_124934.jpg
    2.7 MB · Views: 245
No, I just built each system (8.1 and 10) separately with the other disk not connected (so one disk at a time), then connected both. Luckily, in spite of the "scanning and repairing drive (D:):", the one with Windows 10 on it, when I booted Windows 8.1, Windows 10 booted up just fine. Attached is the Computer Management screen now, with Windows 10 running. Thanks for your caring and help!
 
No, I just built each system (8.1 and 10) separately with the other disk not connected (so one disk at a time), then connected both. Luckily, in spite of the "scanning and repairing drive (D:):", the one with Windows 10 on it, when I booted Windows 8.1, Windows 10 booted up just fine. Attached is the Computer Management screen now, with Windows 10 running. Thanks for your caring and help!
It MAY be that there is an active partition on the 1Tb drive because I use this for "file backup". It has no system on it.
 
Back
Top Bottom