A compression program that handles files with unusual extensions

"WinRAR and the open source 7-Zip will extract any file you throw at it, regardless of file extension. Personally, I prefer WinRAR (mainly because of 7-Zip's clunky UI, but this may have changed since I have last used it) over 7-Zip, but i know many people swear by 7-Zip

Windows cannot do exactly what you are after. The whole purpose of file extensions is to assign each unique extension to a program to open them. In theory, every file extension is a completely different format and therefore a program should not be set as a 'catch-all' for file extensions. Besides, what if you have a .zip file renamed to .jpg? What happens then?

What you could do though is to have an icon in your quick launch bar and drag-and-drop the files onto the program. If the program supports it, they should then launch and extract the file (or do whatever they do with them)."

"I find Izarc has support for a huge number of compression formats including .war files. It integrates nicely with the windows shell and come in a portable flavour too! (IZarc2Go)

See here:
www.izarc.org/

Izarc supports a far higher number of formats than 7Zip and most other archive software. From the website here is a list of features:

IZArc is the best freeware archive utility supporting many archive formats like: 7-ZIP, A, ACE, ARC, ARJ, B64, BH, BIN, BZ2, BZA, C2D, CAB, CDI, CPIO, DEB, ENC, GCA, GZ, GZA, HA, IMG, ISO, JAR, LHA, LIB, LZH, MDF, MBF, MIM, NRG, PAK, PDI, PK3, RAR, RPM, TAR, TAZ, TBZ, TGZ, TZ, UUE, WAR, XXE, YZ1, Z, ZIP, ZOO. With a modern easy-to-use interface, IZArc provides support for most compressed and encoded files, as well as access to many powerful features and tools. It allows you to drag and drop files from and to Windows Explorer, create and extract archives directly in Windows Explorer, create multiple archives spanning disks, creating self-extracting archives, repair damaged zip archives, converting from one archive type to another, view and write comments and many more. IZArc has also build-in multilanguage support.

With IZArc you can open CD image files like ISO, BIN, CDI and NRG.
It is also possible to convert such files from one type to another (BIN to ISO, NRG to ISO).

If you need to send large files to your colleagues, friends or customers who may not have archiving tool you can easily create self-extracting archive that can be extracted by simple double click.

IZArc can be configured to run your preferred Anti-Virus scanner when you open any archives.

IZArc supports 256-bit AES encryption to secure your data.

IZArc is integrated in Windows so you can perform all archiving operations by using right-click menus in Windows Explorer.

If you have broken archives IZArc can help you to repair them with ease."

"If you are using Windows, then right click the .WAR file. Goto Properties, and on the General Tab displayed, press the Change button next to 'Open with'. From there select whatever Zip program you use and press OK. You have now associated your WAR files with your compression program, so that double clicking on them will open them inside your compression program.

The properties box should now look something like this:"