Q:

downloading and installing error: package is not a debian format archive

I'm a newbie to Linux and Ubuntu, and I'm trying to install a package called libstdc++2.10-glibc2.2 I first use wget
wget http://packages.ubuntu.com/dapper/libstdc++2.10-glibc2.2

It gives me saving to libstdc++2.10-glibc2.2.4 so it adds an extra .4 at the end. Then I do 
sudo dpkg -i libstdc++2.10-glibc2.2.4

and it gives me 
dpkg-deb: error: `libstdc++2.10-glibc2.2.4' is not a debian format archive
dpkg: error processing libstdc++2.10-glibc2.2.4 (--install):
 subprocess dpkg-deb --control returned error exit status 2
Errors were encountered while processing:
 libstdc++2.10-glibc2.2.4

What am I doing wrong?

A:

There is no package by the name of libstdc++2.10-glibc2.2. You can check this by going to the URL that you have mentioned in the question: http://packages.ubuntu.com/dapper/libstdc++2.10-glibc2.2.
When you run wget for the above URL, you end up downloading the web page (check the wget command output which states that you are downloading text/html).
If you want to install the C++ compiler and the C++ STL, then just install g++. sudo apt-get install g++.

A:

In general you should install from the package management system (using the Software Centre or Synaptic or Muon or apt-get etc), instead of downloading deb files this way. Why do you want to install libstdc++2.10-glibc2.2? Are you actually using Ubuntu 6.06 Dapper Drake?

