Icons can be created using Irfanview http://www.irfanview.net/ from Irfan Skiljan, Austria.

This free tool can convert a lot of picture formats (also .ico and .gif with or without transparent colour), change the size (edit in pixel, cm or inch) and much more.

The main installation file contains English (default) and German language packages and there are a lot of other languages available.

Icons mus be stored in the 'icon directory' and have defined dimensions