Press Win + X, then select Command Prompt (Admin) or Windows PowerShell (Admin).
In the Command Prompt window, type the following commands and press Enter after each one:
manage-bde -off c:
manage-bde -off d:
BitLocker will begin decrypting the drive. The process might take some time depending on the size of the drive.
Once the decryption process is complete, restart your computer to ensure the changes take effect.