Quote Originally Posted by berzasnon View Post
Still would be a no generic and no guaranteed solution, because nothing assures that the default application will be able to read the data buffer.
Going this way, there is never a generic and guaranteed solution because there might be no default application for a particular file type installed at all and creating a temporary file wouldn't have helped either.

I'm confused; the default system app ought to have read access to that encrypted ramdisk filesystem, and (correct me if I'm wrong) that would only be possible if the whole system has access to such ramdisk.
No, not really. It should be possible to execute the program with special privileges that allow it access to a particular directory, disallowing anyone else.

besides that I can't see the benefit in using a ramdisk.
The 'ramdisk' part is not important here. The 'encrypted' is.

If you're expecting to thwack a magic wand and have a ready solution then that's probably not going to happen. I'm sure your requirement can be fulfilled but you need to get your hands dirty in the low-level system behaviour. You would be much better asking your question on some geek Windows forum than here.