Easiest is if you have PP2010. It's built in. See the image.
Another free way is Windows Movie Maker. It's a Microsoft freebie that may be on your machine already or can be downloaded from MS
Save your presentation as a series of stills (all PP versions allow this) and load them to WMM and create your video. You can add sound at this point as well.
Articulate, which is hardly free, will save as Flash video with a variety of options. There's a 30 day trial if this is just a one shot deal.
Pinnacle Studio and other inexpensive video editors all you to do what I described with WMM with more flexibility. A search for free or shareware will undoubtably turn up more options.
Whatever method you use, compression will come into play. You'll want to choose the least possible for any file size or bandwidth restrictions you may encounter. I'd like to help with this, but without the file in question and knowledge of the target not much I can do. If you can send me the file I'll be more than happy to package it for you if you can provide this information.