Some Canon C100 footage was supplied to me and the files are MOV. Only the audio plays on my Vegas 12 timeline. I can see picture also when using Windows Media Player or Quick Time Player on my Windows 7 computer.
Any suggestions are greatly appreciated.
Are you sure it is camera original footage? What does MediaInfo (http://mediaarea.net/en/MediaInfo) say it is? C100 is just AVCHD at 24MBS, with the options to record in log mode, but you would see an image. What version of Vegas? It could have been recorded to an external recorder in a different format, or converted by someone to another format.
You do not really need Quicktime installed to read AVC.mov files from dslr or other cameras that read it. If the files were converted to another format with quicktime, then you may need quicktime to read them. I really do not see any problems with having quicktime installed. In fact I think you should have Quicktime and Avid's DNxHD codec pack installed, for compatibility with a wide range of media formats.
If you go to properties for the media in Vegas, you should see:
Folder: C:\Program Files\Sony\Vegas Pro 13.0\FileIO Plug-Ins\compoundplug
Format: Sony AVC
Version: Version 13.0 (Build 428) 64-bit
Company: Sony Creative Software Inc.
for AVCHD encoded files from cameras that store this method.