If your browser locks up when trying to view a PDF document, try configuring Adobe Reader to launch the PDF into a new window, instead of within the same browser window:

To open the PDF as a new window:

1. Quit Internet Explorer or the browser you are using.
2. Start Adobe Acrobat or Adobe Reader.
3. Select Edit > Preferences.
4. Select Internet in the list on the left.
5. Uncheck/clear Display PDF in Browser, then click OK - see the following image.
6. Restart Internet Explorer or AOL.