Hello bloggers, some times we need to allow the use of some files into SharePoint 2010. In this case, I’m going to show you how you can configure SharePoint to allow it.
Step One: Go to SharePoint Central Administration
Step two: Click on Security in the quick launch
When you click on Define blocked file types, a windows will be opened with all blocked file types.
Just only must remove the file type, click on OK button and get ready (in this case the CHM text should be removed to allow the use of the file type in SharePoint). Now, if you want to block some file type, the only way is writing the file extension in the same windows and after click on OK button.
I hope this information helps,