Adobe Acrobat 8.1.7 is not compatible with Windows 8. For Windows 8, you might need to use the latest version of Acrobat XI Pro from Adobe.
Adobe Acrobat 8.1.7 is compatible with the following operating systems:
Microsoft Windows 2000 with Service Pack 4; Windows Server 2003
(32-bit or 64-bit editions) with Service Pack 1; Windows XP
Professional, Home, Tablet PC, or 64-bit editions with Service Pack 2
or 3; or Windows Vista Home Basic, Home Premium, Ultimate, Business,
or Enterprise with Service Pack 1 or 2 (32-bit or 64-bit editions)