Intel SSD 535) After Migration, What is this?

[SBaek2]

Hello. I just bought Intel SSD 535 480GB today and install it in my laptop correctly. (Port 1 is HDD that I used, New SSD is on port 2. I didn't get rid of HDD yet. Because of storage.)

I use the driver, for migration, which can be found in intel support download centre. (the name is Intel® Data Migration Software)

Around 1 hour later, all migration works are done and I reboot my laptop. When I reboot my laptop, it was slow. So, I change the BIOS setting to start first with SSD.

It was really really fast. But, I have a question about this.

1.

Can I format E drive? Just right click and click the format button?

As you see, almost same amount of storage are copied. I can guess E drive is my HDD drive because of maximum storage (it was 1TB) So, If the migration working is well, there is no problem when I format it.

2.

What is D drive ? (시스템 예약 which is korean means system reservation, I don't know what that means)

I have no idea about it. I was just using C drive only, but when I migrate my SSD, E drive = HDD good, but what is D? almost 100MB are wasting in my laptop! I enter the D drive but there is nothing. I also check out hidden files. But, all empty. What makes me curious is 28.1MB! Where that storage are working?

3. My laptop's personal information is all missing after migration. Can't I restore it?

For example, when I opened the Chrome, web browser, there is no extension program that I usually used. I have to re-download them! Maybe it can bother me. I don't wanna lose my time for them.

Please read my Question and give me an advice. I need your help please~

ps. Should I have to change the HDD and SSD ports for solving my problem? (That means, now port 1 - HDD, port 2 - SSD but after changing port 1 - SSD, port 2 - HDD)

[AP16]

2) During installation Windows creates a hidden 100 MB partition on disk where the Windows Boot Manager placed. BIOS actually search for Boot Manager, and then Boot Manager starts Windows. So do not delete this partition, disk became unbootable. Just start the Computer Management util from Control Panel and on Disk management select this D:, right-click and select like Change drive letter and remove letter completely to hide it from MyComputer screen.

[SBaek2]

I just set up as you advise and that 100MB partition disappeared. Thanks for your help.

But, I can't solve another problem. Can you advise me about another question?