737 ngx livery

I installed the ryanair livery 800 WL. I ran fsx it appeared but later on that day i ran fsx once again and my ryanair livery had disappeared. I tried to load the livery again but its says it alreadys exists but its not in fsx. I've unistalled 737 ngx but the same message comes up, maybe i haven't completely removed all files within fsx is this the case peeps? Not sure where to find all the PMDG files and i don't want to start deleting files.