How to update eclipse, though some repositories cannot be found

Question

For some time now, I want to use the update functionality of eclipse. But every time, some (maybe obsolete) repositories cannot be found. Still I want the other parts to update, but this error just blocks everything.

How can I work around that problem, i.e. modify the list of checked repositories? Proxy settings are definitely correct, because 'Install new software' works fine.

Error Message:

Some sites could not be found.  See the error log for more detail.
HTTP Server 'Service Unavailable': org.apache.maven/content.xml
HttpClient connection error response code 503.
No repository found at maven.apache.org.
No repository found at subclipse.tigris.org/.
No repository found at github.com/cbeust/testng-eclipse.git.
No repository found at download.eclipse.org/mat/1.0/update-site/.
No repository found at download.eclipse.org/tools/orbit/downloads/drops/R20100519200754/updateSite/.
HTTP Server 'Service Unavailable': org.apache.maven.plugins/content.xml
HttpClient connection error response code 503.
No repository found at github.com/cbeust/testng-eclipse.
No repository found at beust.com/eclipse.
Unable to read repository at dev2devclub.bea.com/updates/eclipse-3.3/wls-plugins/content.xml.
The server dev2devclub.bea.com failed to respond

(http:// and https:// removed due to hyperlink restriction)

From the About-dialog:

Version: Helios Service Release 2 / Build id: 20110301-1815

Answer 1

In the Preferences, type update into the search box at the top. Select Available Update Sites and there you can uncheck or remove the sites you don't want any more.