Hoping that this will help someone who experiences this in the future, I thought I’d briefly write up what happened when I switched my Windows machine from one domain to another, and my iTunes library disappeared.

What happened: My machine had been a member of domain A, and I had redirected “My Documents” and all of its subfolders (noteably “My Music”) to D:\MyDocuments. My iTunes music was in d:\MyDocuments\My Music\iTunes\iTunes Music and the corresponding .itl and .xml files were right above that in d:\MyDocuments\My Music\iTunes.

I moved my computer to domain B, knowing that I would get a new profile and a lot of cleanup work. I should have remapped My Documents right away, but I didn’t. I ran iTunes, and it had to do some reinstallation under the new user profile. It finally opened, showing an empty music library.

After reading some articles online, I thought I could go into Preferences, Advanced tab, and just point iTunes to d:\MyDocuments\My Music\iTunes\iTunes Music. All of the documentation seems to indicate this, but it doesn’t work. It turns out that the pointer in the Advanced tab probably only tells iTunes to look there for the music, but not for the .itl and .xml files that describe the library. iTunes was still looking in my new profile path at a blank set of those files Of course, it took me hours to figure that out.

There are probably two solutions: move the correct .itl and .xml files to the new profile path, or repoint My Documents again so that iTunes finds the existing files in d:\MyDocuments\My Music\iTunes. I chose the second, and it worked well.

By the way, I couldn’t remember how I’d originally remapped My Documents, so I downloaded TweakUI. The only downside was that TweakUI has you individually map My Documents, My Music, My Pictures, etc. The method that I’d used before mapped them all when you remapped My Documents.

One thing that I constantly need and can never remember the syntax for is redirecting stdout and stderr in a Windows batch file or cmd script (actually, the syntax is pretty much the same for *nix shell scripts).

Rather than just a one-sentence note here to remind me, I’ll write a few more sentences as explanation. Hopefully this will save someone a little bit of time

For starters, you can redirect the output of a command to a file like so:

blah.exe > output.txt

That example will overwrite any pre-existing output.txt file. If you want to append to the file, use:

blah.exe >> output.txt

But this only redirects “standard output” (stdout). If your program encounters an error, the output generated by the error condition probably won’t show up in the file. If you want it to show up in the file, redirect “standard error” (stderr) also like so:

blah.exe 2>&1 output.txt

At the moment, I can’t tell you if that will append or overwrite. I’ll check that out and update the post…