Dear alltogether, I am searching for a possibility to determine or calculate the maximum possible file size for a given partition. I have searched for a while now but didn't find anything enlightning. Does someone have an idea for me? Thank you in advance! sbit p.s.: The only possibility I found so far, is retrieving the file system name using GetVolumeInformation, connect it to a small list of Windows supported file systems and its corresponding known max file sizes. But this method has several disadvantages: It is not exact since different partitions with a given file system can have different max file sizes. Also some file system names returned don't even leave me estimate the desired value, the names are empty for instance or "*NT5CSC" or such. Additionally this method doesn't cover coming file systems. Another possibility surrounding this value would be to check for errors or to catch exceptions on each attempt to write too far, but this would harm the speed of the application. Does someone know how Windows solves this?

Check out this comparison table on Windows IT Pro: http://www.windowsitpro.com/article/jsifaq/jsi-tip-9225-what-is-the-maximum-file-size-volume-size-clusters-per-volume-and-number-of-files-per-volume-for-the-fat16-fat32-and-ntfs-file-systems-.aspx Looks like the maximum practical file size is BIG :-)

Dear James, thank you very much for your answer. Currently I'm using a similar table that only is a bit bigger (a roughly twenty entries extract from http://en.wikipedia.org/wiki/Comparison_of_file_systems) since I need to spot to many, many more formattings (all that are able to be write accessed from within Windows, and that are many, with public as well as with selfmade drivers). The software I'm writing, writes huge files sometimes, the 4GB limit is too small for this and I have to cut it to 4GB slices for instance. And here I would like to know a method to know this limit in advance, that I can write with full speed without checking for errors each time. Best regards, Stefan.