Editing the registry has nothing to do directly with VB6, it's something that's of general use for lots of stuff. But you need to be VERY careful when using it, because a mistake will result in a minor annoyance to an unbootable PC.
In your case, use the Run command from Windows Start button, and type in Regedit. When the dialog pops up, the left pane is in a tree view. Highlight the top-most level, then use the Edit menu and select Find. Type in "rscomclNoMsg.dll", and everywhere it is found, check the path, and change it if needed. Then exit.
TOUCH OR CHANGE NOTHING ELSE!