To install db, do the following:

For first time users:
  Just drag the db drawer to the desired drawer on your harddisk and you're
  done. No assignments and such is needed.


Minimal installation:
  Although the archive consists of >70 files, all that is needed for a minimal
  installation is the program itself. 1 file.


For upgraders:
  In db2.4, changes have been made to a lot of files. What may not be obvious
  is the catalog files (for locale languages). All of them have been updated
  (thanks to all translators). If you don't want to copy all files like first
  time users do, don't forget to at least update the catalog files.