Beware of service pack 3 for Microsoft Office 2003. Microsoft programmers have decided that documents created in competitor’s software and older versions of their own can be a risk. If you install this update it does not allow you to open older documents that might be tucked away on your hard drive or in your business.
Fortunately Microsoft has seen the possible problems with this stance and they have created a fix as well as issued an apology. You can read more via John Dvorak’s blog.