The short answer: unless you are creating really huge documents (+10000
pages) or embedding really huge object (an entire HD movie), you will never
come near any of the limits. So don't worry about them.
You are actually asking two different things. On the one hand, you are
asking about the limitations of Word 2007 documents (docx files), on the
other hand you are asking about the limitations of Microsoft Word, the
software program. It is important to differentiate between those two things
as docx files can be opened by many programs (Word, Papers, OpenOffice, ...)
on many systems (Windows, MacOS, Linux, ...). For example, it is possible
that while OpenOffice Writer can handle a particulary large docx file,
Microsoft Word can't, or the other way around. It all comes down to how word
processing programs represent documents internally.
Now, with regards to the limitations. A docx file is basically a zip-file
and therefore follows the limitations of zip-files. That is, the file should
be less than 4GB in size. Next to that, a zip file can't contain more than
65,536 files. Assuming you only add ordinary images, you could add almost
65,000 of them. More complex objects like embedded excel sheets might take
up multiple files and lower that last number.
The above numbers are the theory. In reality, there probably isn't any word
processor which could handle a file with 65,000 images in it or 4GB of
compressed text. (I haven't tested this.)
Concerning the limatations of Word, you might want to check out
http://support.microsoft.com/?kbid=211489 . However, some of the data on
that page is incorrect. For example, it states that there is a max of 32MB
of text. I have seen documents containing over 35MB of pure text being
opened by Word, so I know for a fact that that value is incorrect. I believe
that the data on that page is a lower limit and that for some of these
limitations, the current value might be (a lot) higher.
As to when the file size becomes a problem, it all depends on your machine
(processor, memory, ...) and what you try to do. Some things, like doing a
find/replace operation in a 10,000 page document will always be slow.
Yves
