The first attempt was with an HP workstation that was already running Vista Ultimate. Because Vista wouldn't work with that machine's video card, and because that was a machine that was being used for photo and video editing, installing a new video card was an obvious fix. The upgrade from 32-bit Vista to 32-bit Windows 7 was pretty straightforward. Everything worked right the first time.
The second migration attempt was another big step. I wanted to move to the 64-bit version of Windows 7 so that the dual-Xeon HP workstation could take advantage of its speed and memory capacity. While I'd migrated other machines in the office from Vista to Windows 7, everything was being done in the 32-bit environment. Moving to a 64-bit operating system was a potential challenge for two reasons. The first reason is that Windows 7 would require a clean install. The second is that it wasn't clear which applications would actually work in that environment and which would not.
For those who don't know, the clean install that Windows performs removes your operating system and everything else. Unless you tell the installer otherwise, it'll repartition and format the hard disk. But there is a solution. You can tell the Windows 7 installer not to do the format, and it'll just stash everything in a directory called 'Windows.old' where you can retrieve stuff.
But as you might guess, retrieving stuff manually can be tedious at best. So in addition to planning for the clean install, I got a copy of LapLink's PCmover software and installed that, too. By using this application, you can perform the migration and have your applications, documents, and everything else put back where it's supposed to be.
Once I'd replaced the incompatible hardware (the disk controller, for example) in the machine with products that would work with Windows 7, I uninstalled the applications that the Windows 7 Upgrade Advisor said had to go. Then I installed PCmover, and started the migration.
The actual installation of Windows 7 and the subsequent migration of the applications by PCmover went without a hitch. Preparing for the migration in advance clearly paid off. But that's not the end of the story.
For reasons that remain obscure (despite hours on the phone with Microsoft tech support), 64-bit Windows 7 won't connect to my NAS devices, although the 32-bit version works fine. It won't automatically re-connect to Windows Server 2008 R2. That's being investigated as well. Intel's networking software won't work with Windows 7, and it can't be uninstalled. Intel's tech support has no idea how to solve this problem, but fortunately Microsoft's networking software works fine. And some software, including Qualcomm's Eudora, sets of a security alert every time it runs. Nobody knows why.
While these glitches are annoying when they happen to a single machine, imagine a whole department unable to reach its network storage. Or imagine having to log in to your server manually every time you need to run backups instead of having it happen automatically. It kind of defeats the purpose of having unattended backups, doesn't it?