If you see “There was an error opening this document. A temporary file could not be opened.” when trying to open a PDF file, you may need to clean out C:Documents and SettingsUSERNAMELocal SettingsTempAcr*.tmp
Cheers to “gprellwitz” who suggests this here:
http://www.experts-exchange.com/Web/Graphics/Adobe_Acrobat/Q_20790405.html
Jeers to the MSFT developer who decided that “Documents and Settings” with spaces and mixed caps was a better home directory prefix than “home”