I am using dutch version, so I try to use the right keywords to describe my problem. In settings ->Files and Programs part you can determine which programm to use to open pdf on a website. I would like it to use my dedicated PDF handler "PDF-Xchange Editor". It is als my standard program in Windows I can select "USe standard program in Windows" or select "Other->Xchange Editor". When I do so, it works fine for a while, but then it unexpectectly changes to "save file". I can reselect Xchange Editor again, it works for a while, and then suddenly changes again. I work a lot in a sharepoint environment, which has a lot of pdf-stuf. So you can imagine my irritation level is quite high. It can be good for a few days, or change twice a day. Annoying! Hope yo have a clue to fix this.