I copied the archive contents in my home directory and lauched eclipse.
I asked for a new "hellow world C++ project".
The project does not compile because the words cin and cout are not recognized.
strangely, the #include <iostream> is okay to the compiler.
I am very new to eclipse. I spent the whole day trying to get it work. Your help is more than welcome
That is an error message from the Eclipse static code analyzer CODAN (semantic error) not from the compiler. CODAN depends on a correct index about header files and symbols. The index seems to be incorrect in your case. Select your project and open the context menu. Select Index->Rebuild. This should fix your problem (usually the index is updated automatically).