Pdf downloaf error

[Sara 121]

I have questioned a million times plz rply.when i download a pdf file it takes me to drive pdf viewer and then the pdf file doesnt open when i disable drive it downloads as normal but after a while the downloading status disappear in the status bar and when i open the pdf file in the recent download it says that this file cannot be opened or sometimes it shows in the status bar that 15% or 30% downloaded but disappears after a while and only a few pages had been downloaded

 

[Sara 121]

???????