Yes, just open [FONT="Courier New"]wp-config.php[/FONT] in your favorite text editor. Then update the database name, username, and password to reflect your current info. Just opening the file shouldn't have any effect on anything. It's editing it improperly that can mess things up. Just be careful while you're in there.
Another option (though I haven't tested this extensively) would be to rename your [FONT="Courier New"]wp-config.php[/FONT] file to something like [FONT="Courier New"]wp-config.php.BAK[/FONT]. When you do this and refresh in your browser it should run through the initial setup again. Just enter your new info into the form (making sure you put in the database name of where your current WordPress stuff is) and everything should fix itself. But again, I haven't tested this extensively so just try editing the [FONT="Courier New"]wp-config.php[/FONT] file before you try this option.
Hope that helps.