Hi Eve,
I'm sorry to hear that you are having trouble running GWR on your dataset, and hopefully we can figure it out and get you moving forward quickly! You should not be having trouble running GWR on a dataset with 27,000 points. I just tried to reproduce the problem with a dataset with 30,000 points in 10 sp1 and had no trouble. So, let's try to figure out what is going on.
In order to move forward, can you please provide the following information:
--What version of ArcGIS are you using?
--What do you mean by "no results"? Are the results being created but not added to your table of contents? Are they not being created at all? Are they being saved to a valid path?
--What are the exact steps that you are taking when you run your analysis?
--Can you provide a screenshot of the Messages Window once GWR has executed sucessfully? Make sure that you run your analysis in the foreground if you want the messages window to appear when you are running GWR. Alternatively, you can right-click on the Messages from the Results window and choose to open them after the fact.
Again, I am very sorry that you are having trouble and I'm looking forward to working with you to get the problem resolved.
Lauren Rosenshein
Geoprocessing Product Engineer