TarTool

A simple windows command line tool

- to uncompress and untar .tar.gz (.tgz) files
or
-just untar .tar files

C:\>TarTool.exe
Usage :
C:\>TarTool.exe sourceFile destinationDirectory

C:\>TarTool.exe D:\sample.tar.gz ./

C:\>TarTool.exe sample.tgz temp

C:\>TarTool.exe -x sample.tar temp

More details are on this post --http://blog.rajasekharan.com/2009/01/16/tartool-windows-tar-gzip-tgz-extraction-tool/

TarTool 2.0 Beta supports bzip2 decompression for files with extensions like tar.bz2 and .bz2.

TarTool -xj sample.tar.bz2 temp
or
TarTool -j sample.bz2

http://tartool.codeplex.com/releases/view/85391

Note:

TarTool uses SharpZipLib

See licensing terms of SharpZipLib before reusing this code in one of your projects.
http://www.icsharpcode.net/OpenSource/SharpZipLib/