Are your security settings at "Low"? If yes, set to Medium or higher
and then open the file: you should get a security warning. Disable the
macros- you will be able to view the code but not run macros.

If that doesn't work, when you open the file and get the hourglass,
press ESC to see if that halts the code. Another way to do this- on my
keyboard, yours may be different- is to simultaneously press the CTRL
and PAUSE BREAK keys. (The Pause Break is on my Microsoft ergonomic
keyboard; you should have a similar key that is labeled differently).