Have you looked at installing using the INF versions?
http://ftp.hp.com/pub/caps-softpaq/cmit/HP_Driverpack_Matrix_x64.html
(INF version driver pack (master file))
ftp://ftp.hp.com/pub/softpaq/sp70001-70500/sp70142.exe - Win 8.1
ftp://ftp.hp.com/pub/softpaq/sp70001-70500/sp70143.exe - Win 7
ftp://ftp.hp.com/pub/softpaq/sp70001-70500/sp70142.html - What's included in the driver pack.Win 8.1 INF based files
ftp://ftp.hp.com/pub/softpaq/sp70001-70500/sp70143.html - What's included - Win 7 INF based files