Windows 7と10のデュアルブートですが、パーティションが異なります（2つの異なるディスクも同様）。Win10をWin7ディスクに移行できますが、パーティションは異なりますか？

はい、これは可能です。いいえ、それは悪夢ではありません（IT技術者として、私はこのようなことを頻繁に行います）。はい、ディスクイメージング/クローン作成ソフトウェアを使用する必要があります...その中のAcronis True Imageは1つの（有料）オプションです。

The biggest difficulty for you is that, unfortunately, you appear to have both Windows 7 & 10 installed in MBR mode instead of EFI. EFI would make this stupid simple.

Preparation

1. MAKE BACKUPS! Don't be a cocky bastard thinking you can't make a mistake or suffer a malfunction that makes things go sideways. This process can potentially wipe your data if things go far enough sideways... so make backups first.
2. Get a disk imaging / disk migration program. Others have suggested Acronis... which I have no real opinion of. I would turn you on to Paragon Hard Disk Manager if you don't mind dropping some coin. But you can do this free if you have steady hands by getting a copy of Clonezilla and GParted. Whatever your choice, you will need a bootable CD or DVD of your chosen software.
3. You need to lay hands on a Windows 10 installation DVD. You can download the disk image for one from the Microsoft website using their Media Creation Tool. You must have a Windows 10 bootable install disk of some kind on hand before you disconnect the HDD from the system.

The Partition Two-Step

1. Restart your computer from the disk cloning software's bootable CD/DVD. The steps to do this depend on your computer. Given that you have two OSes running on your computer, I'm going to assume you can manage this. If you are using GParted and Clonezilla... boot the GParted Live CD for now.
2. First you will need to make room on your SSD. To do this you must re-size the Windows 7 partition to be smaller. Keep in mind the smallest you can possibly make that partition is equal to the used space on your Windows 7 partition. However, you must leave free space for Windows 7 to function correctly. One gigabyte is the absolute minimum, but I would suggest no less than 15 GB. You could also resize your Others partition and get the space that way. After freeing some space on the SSD, resize the Windows 10 partition small enough to fit in that space... same rules as before. GParted should make this a rather straight forward process.
3. Now you need to clone the Windows 10 partition to the SSD. If you are using GParted and Clonezilla, this is where you reboot and switch to Clonezilla. In this case we are doing a partition clone... not a whole disk clone. Getting that wrong is where your backups would be needed. You want to clone the Windows 10 partition to the unallocated space you created on the SSD drive. Clonezilla is not exactly user friendly, but it will walk you through the steps.
4. Shut the system down and disconnect the data cable for the HDD containing your old Windows 10 partition. This is both to see what steps we need to take next and to make sure those steps do what we want them to. You'll be able to plug it back in after you're done.

It's Broken!

It is, in fact, broken. How broken depends on which was your boot drive before. The long and short of it is that either your bootloader was on the HDD you just disconnected... and your system is now spewing a cryptic message about missing disks at you... or you are now able to boot Windows 7 but not Windows 10.

Don't worry... it's all part of the plan.

1. In either case, take out the disk cloning software and insert your Windows 10 install disk. Boot from it. Navigate to the page where is has a big button in the middle labeled Install Now!. Do not install now. Instead click the link in the bottom left that says Repair your computer.
   • From the Choose An Option menu select Troubleshoot
   • From the Troubleshoot menu select Advanced
   • From the Advanced menu select Startup Repair
2. スタートアップの修復が完了したら、コンピュータを再起動します。完璧な世界では、Windows7またはWindows10のいずれかを起動するオプションが表示され、両方のオプションが機能するはずです。
3. 必要に応じてHDDを再接続し、BIOS設定でSSDがHDDよりも起動優先度が高いことを確認します。

楽しい！