You misunderstand the function and purpose of file extensions in Windows.
File extensions tell Windows applications what type of file it is. Changing the extension doesn't do anything except possibly confuse things.
Think of it this way. Suppose the file extension "eng" means that a document is written in English and the file extension "spa" means that it is written in Spanish. Now suppose you have a document that is written in English and its file name is HarryPotter.eng.
If you change the file name to HarryPotter.spa, the file doesn't magically get translated. It's still the same file, still written in English, only now anybody (or any application) that looks at the file name will mistakenly think that the file has been translated
to Spanish.
GIF and JPG describe two different formats for graphics files. Again, changing the extension won't change the format of the file. To do that, you need a program that will convert the file from one format to another and then save it with the correct file name
extension.
IrfanView actually is very easy to use. You can either convert one file at a time or you can batch convert an entire folder (directory).
To convert a single file
- Start IrfanView
- Click File > Open
- Browse to the file you want (e.g., Picture1.gif)
- Click Open
- Click File > Save as
- Select the folder (directory) where you want to save the file using the "Save in" drop-down box
- Either keep the old file name or enter a new name
- Click the drop-down arrow in the "Save as type" box and select "JPG - JPG/JPEG Format"
- Click Save
Converting a folder full of GIF files to JPG is just as easy. Suppose your GIF files are in My Pictures. The safest thing to do is to create a new folder (directory) for the converted files. Once you're satisfied that everything went OK, you can move the
JPG files into My Pictures and, if desired, delete the GIF files.
IrfanView will not create a new output directory, so do this first
- Open My Pictures
- Either click File > New > Folder or, if the Common Tasks pane is showing, click "Make a new folder"
- The new folder appears at the very end of My Pictures, with its name highlighted and ready for you to type in the new name and press Enter. If you don't do anything, you'll end up with a folder named "New Folder". For this example, name it My JPG Files
Now do the batch conversion
- Start IrfanView
- Click File > Batch Conversion
- In the upper left of the Batch Conversion dialog window, select the radio button "Batch Conversion"
- Underneath "Batch conversion settings" use the drop-down box to select "JPG - JPG/JPEG Format"
- Under "Output directory for result files" click "Browse" and select the new folder you just created. To find this folder (which is a sub-directory of My Pictures)
• click the + next to "Documents and Settings"
• then click the + next to your UserName
• then click the + next to "My Documents"
• then click the + next to "My Pictures"
• select "My JPG Files" (or whatever you named the new folder)
• click OK
- Back in the Batch Conversion dialog, use the "Look in" dropdown box to select My Pictures (it's under My Documents)
- If you want to convert ALL of the GIF files in My Pictures to JPG, then type *.* in the "File name" box, use the "Files of type" dropdown box to select GIF - Compuserve GIF, and click the "Add All" button.
- A list of all the GIF files will appear in the box at the lower right.
- You can remove some files, if necessary, by selecting them and clicking the "Remove" button
- When you are satisfied that the list of files to convert is correct, click the "Start Batch" button.
- Close the summary window and close IrfanView.
Your newly-converted JPG are now in C:\Documents and Settings\YourUserName\My Documents\My JPG Files