That depends, if your like me and installed CoT as three separate line items: Climates of Tamriel Climates of Tamriel - Dawnguard Climates of Tamriel - Dragonborn Falskaar - Climates of Tamriel Patch Then it will leave the original CoT mod active as it doesn't contain any of the merged plugins (and thus its files were not copied). If you merged them together when installing, then yes you need to copy the esm manually.