I have a program that checks for updates over the Internet. It reads a text file located on our web site that contains the latest version number, then it compares that version number to the running application’s version number and decides whether there is an available update.
If there is an available update and the user elects to download/install it, then the application downloads the single-file installation executable and installs it.
This technique works fine on all my computers except a Windows 7 computer. On the Windows 7 computer, the application instead “downloads” an old version and installs it. That of course causes an endless update loop because the installed application is always older than the version number at the web site.
Of course, that made me wonder where this download was coming from, so I deleted the downloadable application from the web site and the Windows 7 computer was still downloading an old version of the file! How can that be?
Again, this technique worked fine on Windows XP, 2000 and Vista machines some of which were running IE 9 (same as the Windows 7 machine).
I searched the entire Windows 7 hard drive for a copy of the file and deleted all that I could find just to make sure the application wasn’t “downloading” it from its own hard drive, but that didn’t work either.
My question is where is the Windows 7 computer “downloading” this old file from? Is there some cache or something that needs to be attended to? Mystery to me.