What’s happy cloud client?
Happy cloud client is a game downloader developed by Happy Cloud. This download assistant will download the game and make sure all files downloaded without corrupted. The path of the file is C:\users\user\appdata\Local\HappyCloud\Application\HappyCloudService.exe

How it works?
If you run a game, but instead of the game, happy cloud shows up, it means the game not downloaded yet, you need to keep happy cloud open until game fully downloaded. However, happy cloud will try to launch the game before the download process completed. After download the starter core of huge game (258M starter package), happy cloud client will try to run the game and keep download rest of the game. It’s recommend not to turn off the happy cloud client, otherwise you may can’t continue to play game.
File list for happy cloud clien
HCLOTROLoader.exe
HCTeraLoader.exe
npHappyCloudPlugin.dll
detourfileops.dll
HappyCloudService.exe
hcfwexcp.exe
hcgameapi.dll
hcuninstaller.exe
uninstaller.exe
HCDDOLoader.exe
hcwebwindow.exe
detourfileops64.dll
D3DX9_41.dll
d3dx9_x64_41.dll
HCLOTROLoader_fr.exe
managegames.json
Can I remove it?
Once you are sure the entire game has finished downloading, you can uninstall the happy cloud client. Uninstall it won’t uninstall the game.