Theoretically, and in most cases, yes. Occasionally, there can be "glitches."
More important, you may have to switch fonts unless you having OpenType or exactly matching versions of TrueType or PostScript fonts.
I'll assume you mean CS6 and CS3 (Version 3 was CS1). It should open the files, but I only work with Mac files, so I don't know for sure. InDesign's predecessor (PageMaker) could only open older versions if they were on the same platform (newer Mac could only open older Mac), but I think they worked that out in InDesign.
The thing is, if you don't have all of the Windows versions of the fonts used in the document, some text will likely reflow if you use the Mac versions of those same fonts. There is also some tweaking to the text engine from time to time, so you might get text reflow even if you do have the same fonts. If you have a PDF made from the older files, you can have something to compare to tweak the errors.
Lastly, if your goal is to share files back-and-forth with someone using an older version on a different platform, you are asking for trouble. You probably don't want to do that, but many people come here asking if it will work, so I thought I'd throw that out there.
Thanks, Steve . . . I'll try it out tomorrow!
Thanks for the clarifications, Mig. I can't be sure at the moment which version I actually had (since the computer crashed a year ago) but I think I had the CS3 package, so whatever InDesign version that was. I used PageMaker for years (decades, perhaps?) and switched to InDesign when Adobe switched. I still have my old PageMaker files (years of newsletters I produced). Last year after my PC crashed, I got a Mac and have been using it exclusively. I'm hoping to be able to transfer my InDesign files onto the Mac. Luckily, a friend has InDesign on a Mac and said I could try to open my files with his software before I purchase new software for my Mac -- I'm on a time crunch and don't have time to purchase and install a new system before I get a file updated and printed.
I'll let you two know if all worked out okay!
INDesign files are complete compatible on both platform, but problems occur with
- MIising fonts,
- not compatible fonts with your current version of the OS
- not updated or available 3rd party plug ins,
- missing file extensions on Windows (just add them).
- linked files which are not supported in that version in that form
As mentioned above, there will be text reflow issues, but they are insidious since they don't happen until a text frame is access in some way, and they may not be obvious to you at the time since they may be at the end of a story pages away.
There are also frequent enough reports of strange errors with legacy files opened in CS6 or newer (and the bigger the gap in versions the more common the reports) that I advise exporting the original files to .inx or .idml from the original versions and opening the exported files for editing in the new versions. Seems like you won't be able to do that, so the next best thing is to export immediately after opening in your new version, then continue with the exported file (see Remove minor corruption by exporting) a side effect of opening .inx/.idml files is it forces all text to recompose using the current text engine, eliminating the surprise element, but you still need to check carefully for changes to line endings (whcih can affect the space a paragraph occupies) and overset text.