Overall I do like NPS in Windows 2008 but reading the logs is just painful. I know there are aftermarket solutions but sometimes you just need to be able to read these things with something freely available. Notepad++ is part of my standard toolkit and overall is just a great tool. When you open an NPS log you'll notice that each line is over 2000 characters long. Since all the tags look pretty orderly, I went to Language and told it to interpret is as XML. Now I had pretty, colorized 2000+ character long lines. After a little digging online, I figured out how to do a find/replace to insert a carriage return between each back to back tag.
You have to remember to select "Regular Expression" before clicking Replace All. Now everything fits on the width of the screen and now all you have to do is decipher all the tags.