There can be some questions we can't put into other categories. Here you can find them.
If you don't have an archiver-tool to handle bz2 files download the commandline tool from Redhat (please find further information below).
If you would not like to use a command line tool, you can try free tools like Stuffit Expander, UltimateZip, 7-Zip, or Quick Zip. If you have tools like WinRAR or Power Archiver, you can easily decompress the bz2 files with it. If you use Windows Commander, a bz2 plugin for that program is available freely from the Windows Commander site.
The bzip2 commandline tool from Redhat:
Win2k Sp2 users grab the latest version 1.0.2, all other Windows user should grab version 1.00. After downloading rename the executable to bzip2.exe. For convenience put it into a directory in your path, e.g. C:\Windows where C represents your windows installation drive.
Note: lang stands for your language and x for the desired format, e.g.: pdf. To uncompress the php_manual_lang.x.bz2 follow these simple instructions:
open a command prompt window
cd to the folder where you stored the downloaded php_manual_lang.x.bz2
invoke bzip2 -d php_manual_lang.x.bz2, extracting php_manual_lang.x in the same folder
In case you downloaded the php_manual_lang.tar.bz2 with many html-files in it, the procedure is the same. The only difference is that you got a file php_manual_lang.tar. The tar format is known to be treated with most common archivers on Windows like e.g. WinZip.