A .ctg file extension is a computer configuration file. You would need a special type of program or software to open or convert this type of file. To open a .cfg extension file, use a program called Free File Viewer.
The file extention is just .jpg The 128 x 96 is just a file size - it is NOT part of the extention.
Right click on the file then select open. In the new window select to choose a program from a list then choose notepad
A file with a .cfg extension is usually a configuration file. The file will be used by an application to load all the configuration settings. There is no standard format for a .cfg file and how it can be modified will differ from application to application.
A configuration file (.cfg) is normally a text file that can be opened in any text editor such as TextEdit. Some software will create a configuration file that will comprise non alphanumeric characters and so will appear to be random characters.
File Extention
You're computer is regonising a file as an "Unknown File" only because it has no understanding of that file extention. Right click the file and select "Properties", find the extention name (Eg, .exe) and search for software that will read that extention name. If you're having further problems consult someone on a Technical Help Forum.
It is the config/configuration file for the launcher.
A file tree is extention to a file that branches out
You can use Notepad for that.
A file extention isn't needed but when your the file has a file extention the computer can easily find the appropiate program to run it. If a file doesnt have a file extension the computer will require you to find the appropiate program with means more work for you to do
Yes you can open the file with a progam then save it again with the jpeg file extention. When you save (Windows) there will be a drop down list of the file extentions that the file can be saved as or you can change the file extention manually by typing .jpeg. bare in mind some applications you may not be able to save as a jpeg but many generic apps can. you may loose some picture quality though!
A java file it's only a text file. You can't convert a text file into a image file of any type. What you can do is open your java file in your editor an take an screenshot (you must have a key with the label 'print screen' in your keyboard) then open open some image editor like paint and finilly paste and save your image. Or you can chage the java extention for jpg in your java file and have fun trying to open it (sarcasm, don't do it).