Using my handy-dandy Service Capture, I came to find out that IIS and IE use a nifty little piece of crap called an eTag. Basically, an eTag is used between IIS and IE for cache control. If the eTags don't match then the browser goes and gets a new version of the file in question. Firefox and Safari work off of the last-modified date in the HTTP header to determine cache control, or the expiration date, or the cache-control. IE is the only browser that uses the eTag. The only way I could find in IIS to get rid of this eTag was to write an ISAPI filter. I haven't touched, much less thought about C++ in a LONG time. So I downloaded Visuall C++ Express and proceeded into the land of ISAPI filter writing. Knowing I was most likely going to be in over my head, I turned to everyone's favourite resource of knowledge: Google. HOWTO complie ISAPI filters Removing eTag headers I have already compiled and tested this code on IIS 6.0 and included it here in the download link. I don't know if it will work on your server, so it's use at your own risk. If your server breaks, it's not my fault, it's yours. You've been warned. If you are having this eTag problem, this may be able to help you. If you want to be 100% sure, compile the code for yourself.