Quicktime player: Unable to find component

My quicktime will not open.

The problem/ or how I think this happened: I wanted to download a video from youtube so I found a website that said click here to download youtube videos, I did and it didn't work. (it seemed liked it downloaded something, so I figured that I would delete it, but it is not in my Delete Programs List.

The next day I tried making an slideshow/video (I use Adobe Lightroom to make the video and it then creates a Quicktime video). Well, the program told me that Quicktime is missing a component.

I tried poening up Quicktime and this is the error message I get: (it has a big red circle with a white X to theleft of message): This application has failed to start because 3ivx.dll was not found. Re-installing the application may fix this problem.

I have deleted Quicktime and re-installed it. I have gone directly to Quicktime and installed any recent updates. Unfortunately before I realized there was a problem with my computer, I had ran Defraggler and so now my recycle bin is empty.

I am completely at a loss as to what to do.

When I go to the 3vix website it says that the codec already comes with Quicktime... but my quicktime isn't working!

I have a Dell Studio, running on Vista. I do have a complete backup of my computer on external hard drive as I returned my computer to factory settings about 2 months ago.

Any help is appreciated.

Lali