When I try to install Adobe Acrobat Reader 8 on a machine running Windows Vista, I get the error message "The Temp folder is on a drive that is full or is inaccessible. Free up space on the drive or verify that you have write permission on the Temp folder." What's the problem?
This error message probably means you have User Account Control (UAC) disabled, which interferes with something in Acrobat's setup routine. To work around the error, right-click the AdbeRdr80_en_US.exe file, select Properties, and navigate to the Compatibility tab. Select the option to run in compatibility mode and select Windows XP (Service Pack 2), as Figure 1 shows. The installation will now proceed without error.
—John Savill