The upgrade procedure requires that you install version 5.0 separately then import your data from your version of 4.5. However, for the import to function properly you need to keep 4.5 in its original location until the import is finished.
An upgrade guide written especially for going from 4.5 to 5.0 is available here: http://idn.interspire.com/articles/6...../Page1.html
Note: The database structure has completely changed, it's not possible to use the same database tables from 4.5 in 5.0.