I’m a complete beginner to any kind of building, I’ve only ever added ram. On Black Friday I bought a 2tb ssd to replace my 256g ssd. I picked up an enclosure as suggested by a friend not knowing what it did. Last night I had a run at it. My plan was to download an os installer in a thumb drive. Swap out the cards, install windows 10 on the new card and use the enclosure to just transfer data from the old card. I did all this and nothing happened lol. No boot, no bios, no nothing. Not sure if I have to change something so it can boot properly. New plan is to just put the 2tb card in the enclosure to download windows and get it running, then move the 2tb card into the pc and put the 256 in the enclosure afterward, but will having two operating systems connected to my computer fuck anything up, and is it going to be possible to use it as a storage device afterward.

TL/DR What’s my best way to swap out ssd with only one slot on motherboard?