What is an %APPDATA% file on my computer?

[danasuz91]

have been unable to download latest Adobe Reader, so cannot view pdf files. when trying to download newest version i get an error 1606 message, "cannot access file %APPDATA%

 

[ksiemb]

have been unable to download latest Adobe Reader, so cannot view pdf files. when trying to download newest version i get an error 1606 message, "cannot access file %APPDATA%

Various causes.
http://www.bing.com/search?q=cannot+access+file+%25APPDATA%25+&form=MOZSBR&pc=MOZI