OK, I've been torrenting for a looooong time. I use utorrent as well. It seems that the files you are dl'ing aren't video files because I use VLC to view too. Everything is just fine. And I reinstalled XP last night. You need to know what the extension is for the file you are trying to view. Try this:

Navigate your browser to the folder that has one of the video files. I'll assume you are using Windows XP for your operating system.
In the tools menu choose Folder Options.
Once in the Folder Options dialog box click the View tab.
Scroll down to where you see the check next to "Hide extensions to known file types." Uncheck it.

Then look at the file you want to view. It should show .avi or .wmv or some type of video file extension at the end of the file name.

What is the extension?
If it is a form of video then there may be something else wrong.

I can help further but I need to know what the file type is. I willl subscribe to this thread so I recieve notification of posts. ummm....there is no check to subscribe shown here. Go ahead and PM me if you need to.

I edited this post...I changed Show extensions to Hide extensions...sorry for the typo!