Can someone please help me to find out why I can’t update Eclipse so Service Release 1? It has always been nearly impossible for me to make these kind of updates.
I check for updates and the only update I see is the Eclipse IDE for Java EE developers (I think version 1.4.1).
After a short moment I get the following error. All errors say Artifact not found and I have no idea why this happens.

Your Eclipse is configured to query JBoss for updates. First thing I would do is to disable the JBoss update site (actually all update sites other than the Indigo one) and try updating again.