Last week, an IT administrator I've known for a long time called me in panic mode. His agitation surprised me; he's incredibly meticulous with his network. My friend rarely has any major problems because he's extremely careful to test and retest changes to system configurations, applications, and OSs before rolling out the changes.
However, a barrage of angry users were calling him. He had just finished rolling out Windows XP onto 150 existing systems (upgrading a mix of Windows 2000 and Windows 98 machines), and half of these users had called the Help desk to complain that they couldn't log on and that all of their password-automation functionality had disappeared. My friend was concerned—the behavior wasn't apparent during his tests, and the upgrade wasn't affecting any of the new XP installations.
He wasn't too thrilled when I told him that what he'd experienced was a known problem, and that if he checked, he would find that all of the affected computers had been running Win98 before the upgrade. Passwords for logons, domains, network shares, and DUN connections aren't preserved when you upgrade from Win9x to XP because password storage in Win9x isn't secure. To make matters worse, recovering the passwords is impossible after you complete the upgrade.
Unfortunately, this kind of problem is difficult to foresee. The problem doesn't show up when you run the application-compatibility testing, and you probably won't discover the situation in lab testing. The problem is minor and solvable, but when you multiply the situation by dozens or hundred of users, the problem can suddenly become an IT administrator's headache.
My friend's experience served as a reminder that I shouldn't forget about Win9x and its problem set. I've used XP, Win2K, and Windows NT 4.0 almost exclusively since the release of NT 3.51, and readers occasionally remind me of Win9x when I write tips for this UPDATE. But for me, Win9x is a minor problem because I'm not required to support or deal with Win9x users. All of my business environments use some derivative of NT. My only ongoing Win9x experience occurs on one computer in my home network that runs the OS to provide a platform for older games that my children play.
When many other IT professionals and I think about the Windows client OSs, we do so with a curious tunnel vision. We all need to keep the Win9x situation in mind and take steps to hack away at our tunnel vision before it causes problems.