So, you don't want to know the amount of available memory, but the amount of
available disk space? I'm not sure that you will ever be able to reliably
predict ahead of time whether X is enough memory to save a file of size Y or
not. You have to deal with cluster sizes, just like you do on the desktop
when saving to disk. You can take a look at GetDiskFreeSpaceEx() in the C
SDK. You should be able to P/Invoke to that. Probably the 'right' way is
to just try to save and, if you get a disk-full exception, report that to
the user or take suitable automatic action as a result. I don't see
DriveInfo in .NET Compact Framework, so I think that P/Invoking is probably
going to be necessary.
Paul T.