Lost “file type”

I am using notepad to edit batch files but wanted to change the “edit” file type option so that I may edit the batch files in wordpad. My problem is, I now have no associations for the .bat extension. I have tried and am now able to edit the document again in notepad but when i double click on the batch file to execute, it comes up with a dos prompt and does not “run” the batch file. Can someone please help me!!!!!