Word opens when ever I download a file...

Hello,

Whenever I download or click to open a PDF file on my computer, a blank word document opens instead. When clicking on the file, a box pops up asking what form of word I want my file to be converted to. When I hit cancel, a blank word document opens. The document is still added to my downloads, but I am getting really annoyed with closing word. Any ideas as to how to stop this?

Thanks,
Erica