Hi Stepdragon,
sorry for the long time to answer.

Here's a little Code to test the DataGridViewStarRateColumn. Unforunitly it doesn't work the way i like.
StarRateTester.zip

In the Sample the lower DGV is the one with der Starrate Control. Click on a Rating and see the Control.

I like to have a Control to display decimal values als Stars in a Datagridview and want to have the ability to change the Value by clicking on the stars. The only thing that work is when you click on a Rating the Control is displayed...but when you change the value and leave you get an error.

I have no more Idea what i could do. It would be very cool if you'll find a way. I don't want any workaround and want to understand how it coud be made.

Thank you for having a look at this!