As long as everything is running fine, then these can be deleted. As long as everything is running fine, then these can be deleted. As long as everything is running fine, then these can be deleted. I would suggest moving these to a temporary directory just in case you miss the sounds. They can all be deleted as well.
Image files can take up a lot of space.
View them and erase all of the ones you don't want. The Windows directory will have quite a few BMP files as they are used for wallpaper. You generally don't want to delete EXE, COM, or BAT files as these are programs. Any files in your root directory not mentioned above. Check the file's date - if it's recent, most likely it's still being used.