Hi i must tell you all about a great program that make texturebuilding and pk3packing mouch easier it’s called total commander.
once you have rename a pk3 to zip it will atomatically open pk3s as zip and you can directly pack files (bsps) while testcompiling it takes about 3 minits to compile and load the map in ET (small maps)(depends on compilingtime)
it has two disc windows and you only need to drop files over from one window to the other.
link: http://www.ghisler.com/
or search “total commander” on google…

A special program made for pk3 and mapping. Much better than winrar etc. Perfect for my use and great file size in result. And ofc you can use it by default pk3 handler with windows.
thx Nail