You shouldn’t ever change anything in the .hg
folder and shouldn’t ever delete files from that folder. Ever.
But forgetting about that part of your question, what are you trying to do? If all you want to do is get the LAM project to a different computer, using Send/Receive is usually the best option.
If that’s not viable for some reason, go to File–>Backup Project to File, save the resulting .zip file to a flash drive, transfer it, and use File–>Restore Project from File to restore that .zip file. You shouldn’t need to mess with the actual LAM folder at any point.