Upgrade SSD Criteria

[seminPark]

Thank you very much for all your help.

I'm worried that my English will be delivered well because of my poor English

I need accurate information to upgrade the SSD in my laptop.

the present
256Gb SSD + 1Tb HDD

Expected Upgrade
1. 512Gb SSD + 1Tb HDD
2. 512Gb SSD + 1Tb SSD (Maximum 2TB SSD)

Manual says that installation is only possible method 1
Is it impossible to install two SSDs like method 2?

Additional question
What's the best way for me to move the entire data and OS installed on my current SSD to a new SSD?
As far as I know, the laptop doesn't have an extra SSD slot, so it's impossible to connect at the same time.

[Huffer]

The Manual does not define what is possible to install. You can install an M.2 SSD and also a 2.5 inch disk either SSD or HDD. Either or both can be as large a capacity as you can find in the market. You can make a backup image of the existing 256 gig SSD and if you have enough space on the 1 TB HDD you can store it there and then use that image to recover onto a new larger SSD. If you do not have enough space on the HDD, you can use an external USB  hard drive to hold the backup image. You could also get an external M.2 SSD to USB adapter, and use it to copy the 256 gig SSD contents directly onto a new larger SSD inside the laptop. Macrium Reflect Free works well for any of these options.  Post back if you have more questions about all this.