Problem transferring profile to a new computer

Hello: I am trying my hardest to figure out how to move my existing Firefox profile folder (with bookmarks, passwords, etc.) to a new system. I have tried repeatedly to take the contents of the existing profile, and past them into the default profile on the new system. None of the information shows up. The existing profile is version 115.25.0, running on a Windows 7 Pro platform. The system I'm trying to move the profile to is a Windows 10 Pro 64 bit system. I installed the same version of Firefox on the target system. All the files from the existing system seem to copy over to the new default profile folder fine, but no luck when Firefox is opened. I also tried copying the entire profile folder over (leaving the folder name intact), and removing the default profile that was set up by Firefox. When I do that it just gives me a message saying it can't find the profile. Don't know what else to do here. I have a lot of data in the old profile that I don't want to have to re-create. -S