I'm installing stuff (flash player, graphics driver, software) on Slackware 14.1 and it doesn't work right. In the old days I would untar the package, run ./configure, make and make install and it would get installed under /usr/local but now I find the packages don't support that. I tried installpkg but it doesn't do it right, it puts everything under / which is wrong. I've got libxxx.so under / as well as directories for stuff. It seems strange that packages don't get installed properly. My question is this: Am I missig something? Is there a way to get software to install properly?

Yes and yes. http://docs.slackware.com/slackware:...ement_hands_on
For some of what you are trying to install, e.g. flash, you may find a prebuilt package at http://taper.alienbase.nl/mirrors/ (Look under people/alien/slackbuilds).

Your technique is for building programs from source, rather than installing a package.
Another useful page. http://docs.slackware.com/howtos:sla...lling_software

Okay, I read the pages you referenced but I didn't see anything that answered my question. Let's look at a couple of examples. I needed to get a flashplayer plugin so I went to the Adobe site and DLd a package. I ran installpkg and it extracted libflashplayer.so and put in in / rather than the proper place /usr/lib/mozilla/plugins/ (or similar). Why do I have to look up the proper destination and move the file? At least that one is solved. I have another package which came from the Nvidia site and supposably gives me a updated driver, which I expect to be a module. Running installpkg creates a directory in the / dir which contains a lot of stuff but I don't see clear docs describing what to do with these files.

The installpkg tool is for installing a Slackware package. It is assumed that the contents of that package is properly formatted. The installpkg tool is _not_ for doing a task such as you describe. If you look at the documentation I pointed you to, you would seen the src2pkg tool, which is designed to perform that task. However it is a third party tool, not an official Slackware tool.

When it comes to the nVidia driver, you can either:
- install using a SlackBuild script from SlackBuilds.org or
- use the nVidia installer directly.
My preference is to use the nVidia installer directly as my experience has been that it works without problem. However it is a rare exception. I almost always install third party software using a prebuilt Slackware package or a package built from a SlackBuild script. The reason is that it means that uninstalling and updating software is done cleanly. Using the Slackware package system takes a little getting used to, but once mastered you would not have it any other way.