How to copy only the content of drupal installation (migration)?

I have been told to upgrade Drupal website from very old version (probably 4) t开发者_JAVA百科o the newest one (7). I tried different approaches, without success, due to various incompatibilities. I guess the best way to do that is to freshly install Drupal 7, copy the template and then the database. However, probably if I just copy database from old version it won't work, because even the table names are different. So my question is: is there a way to do that, i.e. to copy somehow only nodes and upload it to the new installation? Or maybe some other way? Has anybody approached this problem in the past?Any advice will be appreciated.

There is a very similiar question here: Is it possible to upgrade Drupal from very old version(4) to the newest one(7)?