Cannot open PDF files.

Have you any idea how I can get out of this pickle?

I had no problem with this with my old computer, yet I have identical software on it!

Performing research on the Net I am trying to view PDF files online many times a day, but each time I click on the link the PDF won't open and gives me this error message.

"The Adobe Acrobat Reader that is running can not be used to view PDF files in a Web Browswer. Please exit Adobe Acrobat Reader and exit your browser and start again."

I don't have Acrobat "running", as the message states. I have only the browser (Firefox) running. Have tried Chrome and IE, same message.

I had two versions of Acrobat installed: I have Acrobat 5, which is the PDF writing program, and I also have Acrobat 9, which is the free download which only reads PDFs and cannot write them.

This problem occurred when I had only Acrobat 5 installed, i.e. when I first set up this new computer a month ago, and I later downloaded 9 in an attempt to fix the problem.

As I said I had both 5 and 9 installed on my old PC, only changing PCs has caused this problem.

Now I have uninstalled Acrobat 5 and have only the 9 reader installed, but I still get the identical error message.

The only way I can view any pdf file from the Net is to right-click Save Link, save the file then open it on its own. But sometimes this does not work as the file won't save.

I'm a full time researcher, and am being severely hampered in my research since most things are in PDF these days.

Thank you

Helena