I installed whatever the most recent service pack is for XP (SP3?) a few months ago. Because of that, I could no longer use my AVG, so I'm now using Avast. (That part is not a problem, but I thought I'd mention it in case that might somehow be helpful to know.) Anyway, I cannot open a PDF any more unless I save it to my machine first, then open it from there. With Firefox it immediately locks up my machine. With IE7 it will open the Adobe Reader window, but no file will appear. Since it's not always obvious that a link is a pdf, this happens waaaay too often and is driving me nuts. Can anybody tell me what to do to make the PDFs open via the web, as they should?

Thanks!

Bumping up. Anyone have suggestions?

Opus 88, Have you opened your Adobe Reader and click on Edit>Preferences and in the left hand column you will see internet. Make sure the boxes are clicked to view pdf in web pages.