Recently I have been trying to download trial versions of video editing software. With two of them the download finishes, but when I run the installation process I am informed that some of the downloaded files are corrupt. I have sought help on the relevant help forums but am always told to keep repeating the downloads until the installation finally works. I have done this many times (with my anti-virus on and off) but without any luck. The third trial downloaded successfully (like the others) but when I click on the application in order to install it, nothing happens. There is obviously a problem on my computer but I don't know what it is.