Microsoft have brought out a docx format now meaning that old versions on word, excel and powerpoint can not open documents.
If your using 2007 make sure to save documents when sending to other people in older format.
Office 2007 button (Top left hand corner) -> Save -> Office 2003 version (*.doc)
The FIX:
Download this Compatability Pack

Want to edit convert and change and video to another format check out Squared 5.

You can use MPEG Streamclip to open and play most movie formats including MPEG files or transport streams; edit them with Cut, Copy, Paste, and Trim; set In/Out points and convert them into muxed or demuxed files, or export them to QuickTime, AVI, DV and MPEG-4 files with more than professional quality, so you can easily import them in a DVD authoring tool, and use them with many other applications or devices.
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