Windows 7: really need help installing and running qg4 in dosbox

So I open dosbox .74 I mount my c drive mount c c:/dosgames then mount e e:/ -t cdrom then e: install and go thru prompts now the directory that it lists is c:\Sierra\qganth\qg4cd so then I install the full version and finish the prompts and it brings me to this screen... Illegal command drive J does not exist! Illegal command what. Unable to make: j:\SIERRA. Illegal command: makepath. Illegal command: makepath. Illegal command: makepath. Unable to change to: J:\SIERRA\QGANTH\SAVES\ERROR52\DOS. copying files please wait illegal path. Quest for glory 4 installation complete... To play QG4CD go to J:\SIERRA\QGANTH\QG4CD and type QG4CD
press any key to continue... At this point the screen is froze and there's nothing I can do please help!

did you downloaded the game? is it an original copy?