Why doesn't the Version tab show up for very large files?

Raymond Chen

If you have a really large file and try to view its properties in Explorer, you may find that the Version tab doesn’t appear. What’s going on? The Version tab uses the GetFileVersionInfo family of functions to obtain version information from files. It so happens that the GetFileVersionInfo function works by calling LoadLibraryEx(LOAD_LIBRARY_AS_DATAFILE) and then using functions like FindResource to locate the version resource so it can allocate a buffer to hold the version resource plus additional data to assist in character set translation. If the file is larger than the available address space in the Explorer process, then the call to LoadLibraryEx will fail due to lack of address space into which to map the image. Library not loaded means no version resource to show you. When we explained this behavior to a customer, the customer wanted to know the exact file size at which the problem occurs. There is no single exact file size at which the problem occurs because the amount of available address space is determined by large numbers of factors which cannot be boiled down to a simple description. It depends on the pattern of memory allocation that took place inside Explorer, which shell extensions and DLLs got loaded at what point in time, where they got relocated to, which ones got unloaded relative to others loading, how much memory they allocated and where those allocations ended up. It’s like asking the airline, “I know that the later I make my reservation, the less likely I’m going to get the exact seat I want. What is the cutover point before which I will get a window seat and after which I won’t?” There is no specific point in time where “all reservations before this point will definitely get a window seat, and all reservations after this point will definitely not get one.” It all depends on the pattern of requests before you make your reservations. Indeed, it’s even possible that if you had made your reservation later, you would have gotten that window seat, because somebody who had a window seat called in a cancellation.

One customer apparently didn’t understand the unpredictability of the cutover point and asked, “Is there a way to change this limit?”


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