I have a very large PowerPoint presentation (.pptx) containing a large number of embedded videos. Both to improve performance and to reduce file size (currently around 950 MiB) I am attempting to use PowerPoint's "Compress Media" option. It begins by working fine, compressing my videos happily, but then freezes about a third of the way through the presentation. I have to crash via Task Manager (well, Proces Explorer actually) to recover. It is NOT consistently the same video. I am able to compress other presentations of similar size. The .pptx is on my server. I am running PowerPoint 2010 on Windows 7 x64, with a Core i3 CPU and 4 GiB of RAM; my video card has 512 MiB. Neither Process Explorer nor Resource Manager show any hardware being maxed out. What is likely causing this freeze, and how do I stop it?