The girl I bought them from downloaded them from her computer, and when I try to do it on mine, it doesn't let me.
Try a manual install:
Unzip the zip file if needed.
Create a single folder to put them in, if not already in one.
Copy that folder to your LR presets folder:
On Windows: C:\Users\MyName\AppData\Roaming\Adobe\Lightroom\Develop Presets
Retrieving data ...