It does not write keys to the host computer's registry database. When you unplug your drive, no trace of the software remains.
The "Portable" version flips this model. The concept is derived from the "PortableApps" culture: software that requires no installation. You download a compressed archive, extract it to a folder, and run the executable. When you are done, you delete the folder, and the program is gone—without a trace. ld player portable
If the above method fails, run LDPlayer inside a portable VM like – heavier but more reliable. It does not write keys to the host