Okay, a little difficult to piece together, but I think I understand. Honestly (and this is an educated guess without further info), it sounds like you may have downloaded malware that damaged your system. What are the specs for your machine? What was the critical error? Where did you get the netbeans download from? Do you have an antivirus enabled on your machine? Do you remember anything about the "extra files" that were opening?
Most importantly, do you have a backup of the data on your computer before this happened?
Most importantly, do you have a backup of the data on your computer before this happened?