: Right-click the AutoCAD 2009 setup.exe and select Properties . Under the Compatibility tab, check "Run this program in compatibility mode for" and select Windows XP (Service Pack 3) .
Windows Media Format 9.5 is a standalone player (like Windows Media Player). It is a runtime package —a set of codecs and system files that allow other applications (like AutoCAD) to read, write, and manipulate WMV, WMA, and ASF files at a programmatic level.
Even after installing Windows Media Format 9.5, AutoCAD 2009 may still complain. Here is the fix: