Easiest - IE Png Fix
This png fix uses a blank 1×1 .GIF and a .htc file to render png files in IE
If you have used pngfix.js from http://homepage.ntlworld.com/bobosola/ then you know that it doesnt support PNG files loaded as backgrounds from CSS, but this fix will add support for them
Usage:
You only need to add one line of CSS for this to work.
img { behavior: url(iepngfix.htc); }
upload the files blank.gif and iepng.htc into the same directory as your server
[they can be downloaded here]
remember if you are using this on something like wordpress where ur html files are generated specify an absolute path to iepngfix.htc
Original Article here and easy to follow tutorial here