How to Stop IE6 Caching Downloads

Update: The method described below will cause IE7 to drop the extension. A modified version is pending.

Until recently, I had no idea that IE6 cached downloads. I knew page and image caching were issues, but I didn’t know if affected exe’s and zip’s as well.

FlowBreeze 2.0 was released 11 days ago, putting some of the 30-day trial users in the bubble. They were using the 1.4 version, so they’d come to the site, download the new version, and install … Version 1.4?!?

One customer didn’t think I’d believe him, so he took screenshots of each step: clicking the download button, saving to the Desktop, and running the setup file, which clearly said version 1.4 on the screen.

Thanks to the folks on the BoS forums, I figured out the problem and wrote a little Javascript to resolve it. If you are running dynamic pages, server side scripting would be more robust. But if you’re all HTML like I am here at BreezeTree then this should work in a pinch:

function UpdateDownloadLinks() {
var i;
var linkLength;
var linkType;
var linkCount = document.links.length
var randNum = Math.round((Math.random()*10000));
for (i = 0; i < linkCount; i++) {
linkLength = String(document.links[i].toString()).length;
linkType = String(document.links[i].toString().toLowerCase()).substring(linkLength, linkLength - 3);
if ((linkType == "exe") || (linkType  == "zip"))
document.links[i].href += "?fid=" + randNum;
}
}

(N.B.: I haven’t played with Javascript in years, so if this code sucks, leave a comment below and let me how to make it unsuck.)

The script downloaded by clicking here.