Even if the update breaks applications on, say, only 0.5 percent of its client base, a large vendor with hundreds of millions of customers is looking at potentially a million or more angry end-users. It's not a way to grow market share.
But if updates cause problems on only a small minority of systems, is it fair to leave the larger majority at future risk? I wish more vendors would warn users during the install/update that the older versions might be left behind for compatibility reasons, then give users the option to remove the older version during the new install. Enterprise updates could just install the patch with a switch that forces the old version to stay or be removed.
If this problem of multiple application versions is relatively new to you, or if you haven't done anything about it, develop a new patch plan of attack and resolve the risk. First, scan for and detect older application versions. When you find these old program versions, make sure they are no longer needed to support other currently used applications.
If not needed, remove or uninstall the older version. Sometimes this is as simple as deleting the older files and/or directory. Occasionally, some programs fight the uninstall process. For example, some older versions of Flash will not let you delete the file, regardless of your admin status. If this happens in Windows, try the Add/Remove Programs applet, run the program's custom uninstall program, change permissions to prevent execution, enable the kill bit (if it's an ActiveX control), or search the Internet for additional methods. Finally, implement a new patching policy that takes older, left-behind application versions into account.
Software vendors, if you don't uninstall the previous version, let us know about. Better yet, give us the choice during the upgrade to keep or kill the old version. You'll get bonus points if you don't try to sneak unrelated third-party software into your patching process.
Sun podcast and yours truly
Last week, I spent half an hour with two Sun Microsystems podcasters, Brandon and Don, discussing identity theft. I had more fun with their podcast than any other I've done over the past year. I found the hosts to be very knowledgeable and open-minded. You can listen to the podcast in MP3 format or subscribe using iTunes.