1) It doesn't matter where you move your data. You just need to clear space so that you can shrink the partition. Only 21GB? You said your backups were 200GB in the other thread. How do you only have 21GB of data?

2) You can't shrink the partition if it is filled with files. That's why I said you need to move data to another drive first. A partition is a container. If the container is full, how can you shrink it?