Sensenacai: So I tried the Scan Folders feature and while it does import the games from my external HDD after clicking "Select Folder", the game folders stay on the external HDD that when i unplug it I can't play any of the game even though they are in my "installed" library because the games files are nowhere to be found on the GOG Galaxy folders on my PC.
I have tried copying a game file from the external HDD to the Games folder in the GOG Galaxy file but it doesn't work. Nothing shows up in me installation library on Galaxy.
For the first part, I think you misunderstood.
You first need to copy your game folders to your PC, into the usual install folder.
Then you do the Scan Folders bit, to scan on you PC, not relocate from Laptop to PC, as I am not aware that Galaxy does any such thing.
For the second part, it sounds like you were expecting Galaxy to automatically pick up game folders copied to the Games folder in Galaxy. That won't happen, and it is why there is a Scan Folders option.