I have added these files (symbols and subcircuit models) to the LTSpiceIV directory to be able to use 
them in the simulation. 

I do not own these models nor have I created them! I just bundled them together to make life easier.

Go to C:\Program Files\LTC\LTspiceIV\lib and place the files into the same subdirectory as they are in now.

For example put the file LM317.sub into the directory sub and the file LM317.asy into the folder sym\Misc