I installed Adobe Reader 9 but the browser plug-in will not work with IE8 or Opera 10 Alpha. Since the problem occurs in both browsers, there must be some incompatibility with the Adobe Reader 9 browser plug-in and Windows 7 Beta. I did try a repair install of Adobe Reader 9, but that made no difference. In Opera I found I can choose to open with the default program AcroRd32.exe which will open the pdf in a separate instance of Adobe Reader instead of within the browser using the Adobe Acrobat plug-in. I would prefer that pdf's I download open in the browser window. This works in Vista SP1 and XP SP3 with Opera 9.63. I have not tried to find a solution for IE8, but at any rate I would like the browser plug-in to work.