Reboot loop at the beginning of fresh Windows 10 install on a SSD

Well, the last step that I can think of is to see if it is a problem booting from USB/DVD or not. Use the USB adapter again to connect the SSD to the notebook. I like using MiniTool Partition Wizard to do custom partitioning:
Best Free Partition Manager for Windows | MiniTool Partition Free

Since the desktop looks like it is legacy BIOS, you will want to re-initialize the SSD as MBR, deleting all the partitions on it. Create a single, 5 GB primary partition, formatted as FAT32 at the very end of the drive, mark it as the active partition, and assign a drive letter to it. I am going to use W: for Windows. In MiniTool Partition Wizard it should look like my Disk 3 (but yours will be larger). Make sure it is FAT32, Primary, and Active:



Mount the Windows 10 ISO file and copy all the files and folders from the mounted ISO file to the SSD.


Then you will open a Command Prompt (Admin) and run the following commands - assuming you assigned drive letter W: to the partition on the SSD:

W:
cd boot
bootsect /nt60 W: /force /mbr

NOTE: there is a space in front of each "/" above.

Then you should be able to install the SSD in the desktop computer and boot from it into Windows setup and install Windows 10 to the remaining unallocated space. Do not delete the 5 GB FAT32 partition because, unfortunately, that will be where you boot files end up being.

Here is what the Command Prompt (Admin) commands look like in the command prompt window:

Code:

Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.

C:\WINDOWS\system32>W:

W:\>cd boot

W:\boot>bootsect /nt60 W: /force /mbr
Target volumes will be updated with BOOTMGR compatible bootcode.

W: (\\?\Volume{f07b1dd9-91a6-11e6-8f71-7c5cf84fe038})

    Forced dismount complete, open handles to this volume are now invalid.

    Successfully updated FAT32 filesystem bootcode.

\??\PhysicalDrive3

    Successfully updated disk bootcode.

Bootcode was successfully updated on all targeted volumes.

W:\boot>Exit

If that works, that tells you that the problem was the computer booting from the USB flash drive and/or the DVD drive. If it does work, come back and I can tell you how to get the boot files off the 5GB partition so you can delete and reclaim the space for Windows.

Wow, thanks a lot for that guidelines!
However, before trying that, I must add that:

a) The computer can boot from DVD for sure. During my tests, I have used a couple of linux bootable CDs (including tools like Parted Magic to look at the SSD partitions, etc), and they booted fine (also windows on the HDD was installed from a DVD too). Can't remember booting from USB before, but I think it's OK too.

b) I did a try connecting both the HDD and the SSD simultaneously, with boot priority set to the HDD. The result was that the *HDD* didn't boot. Windows began to load briefly, then rebooted. With only the HDD installed, it boots fine.

Having said that (the system *can* boot from DVD and probably from USB too), do you think that your test still worth a try? I can do it anyway if you're in doubt.

Queenland said:

b) I did a try connecting both the HDD and the SSD simultaneously, with boot priority set to the HDD. The result was that the *HDD* didn't boot. Windows began to load briefly, then rebooted. With only the HDD installed, it boots fine.

Having said that (the system *can* boot from DVD and probably from USB too), do you think that your test still worth a try? I can do it anyway if you're in doubt.

No, I don't think it would be worth it to try. It sounds like something if physically wrong - a hardware incompatibility - when the SSD is connected. I don't think you are going to get it to work with that motherboard and that SSD. Do you have the latest, most up to date bios flashed on the motherboard?

Yes I do, it has the latest bios version (F14) for available for the Gigabyte GA-P55A-UD3P motherboard.
Thank you very much for your time anyway.
I am also thinking that it is a hardware incompatibility of some sort.
I just have purchased a USB case to use the SSD as a backup external drive, and will probably gave up trying to install windows on it on my current desktop computer. Oh boy