You can find community-preserved versions of the Debian 4.0 r9 i386 CD and DVD sets on Archive.org.
The most reliable source for full CD and DVD ISO images is the cdimage.debian.org archive . It hosts all point releases from 4.0r0 to the final 4.0r9 .
Includes Alpha, ARM, HP PA-RISC, Intel Itanium (IA-64), MIPS, IBM S/390, and SPARC. Key Features of Debian Etch Debian 4.0 introduced several landmarks for the project: Where to still find a Debian 4.0 (etch) ISO? - Server Fault
To , you must use the official Debian project archives or trusted third-party repositories, as this version is no longer the current stable release. Released in April 2007 and superseded by Debian 5.0 (Lenny) in 2009, Etch has been archived and no longer receives official security updates. Where to Download Debian Etch ISO Images
Because Etch is an "archived" release, it is not available on the primary Debian download pages. You can find it at the following locations:
Debian Etch was known for its wide hardware support. You should download the version that matches your hardware architecture: For older Intel/AMD processors. 64-bit PC (amd64): For modern 64-bit systems. PowerPC: For older Apple Macintosh and IBM servers.
For those with limited bandwidth or who prefer to build their own ISOs from mirrors, Jigdo files for Etch are still available in the official archives. Supported Architectures