In an effort to get some issues resolved, I'd like to install Rosetta on 10.6.2. How can I do this without trashing apps & data? My concern is that, when I install from the installer disk, the apps & data may be erased. Is that true?

Simply launch an app that requires a PPC processor and you will be asked if you want to install Rosetta. You reply in the affirmative and it is done. No install disc is required and nothing will be overwritten nor any data lost on your system. Or at least that is the way it worked on my wife's MacMini.

That may have happened once in the past, but it's hard to remember. Is there some way I can verify it, such as searching on Rosetta with Spotlight with system files included?

Here's the search result:

dyld_shared_cache_rosetta.map
dyld_shared_cache_rosetta
com.apple.pkg.Rosetta.plist
com.apple.pkg.Rosetta.bom
RosettaVersion.plist
RosettaNonGrata

Are these files confirmation that it is installed on my machine? The creations dates are not all the same, but that could be due to the two system updates, couldn't it?

Since I have not "installed" Rosetta on my iMac and EasyFind turns up no file names containing rosetta, I would guess you have installed Rosetta at some point. Someone else may know a command line trick to determine if it is installed but the only way I know of is to attempt to launch a PPC app. (You can tell if it is PPC by doing a Get Info on the application file and under General the first item on the list is Kind. If Kind is Application (Power PC) then it will require Rosetta to run. If you launch it and it runs then Rosetta is installed. If Rosetta is not installed then you will be prompted to install it.

I did as you suggested and the PPC application opened just fine. "Kind" in Get Info showed (Application PowerPC). I guess that answers the question. Thanks a lot. I really appreciate your taking the time to help me out.

You are right. I did install Rosetta for sure and have the same files as you mentioned. I did the installation through custom install enabling Rosetta manually in the installer and did not lose anything, as expected.

That's what I was thinking of doing, but I was scared off by the fact that the Custom version also showed "Essential System Software" with a check mark that I could not uncheck. I was concerned that installing those files might erase the whole volume and I didn't want that to happen. Thanks for the info. It may come in handy again sometime.

Another way to install Rosetta after the initial install, is to insert the Snow Leopard Disk and click on the folder Optional Installs. In that folder is a File
Optional Installs.mpkg. From There you can Install Rosetta by itself. You can also install other Printers. Languages, Quicktime 7 etc individually

Thank you. That sounds very handy.

I tried it. That's a very handy way of doing things. Thanks again for the heads up.

You're very welcome. I was glad to be of help. Mark