If you are running any type of malware suites, virus scanning or Internet security suites, disable them before running the Installer.
And when you start the installer, right click and run as administrator. The installer is designed to elevate the rights automatically, but it looks like something may be preventing that from happening.
And lastly, you could try re-downloading the installer before starting all this. It could be one of the files in the payload did not unpack correctly.
I am running 1.4 on my desktop OK except Fldigi won't connect with DAX, but I had problems with that on 1.38. When I first ran 1.4 all the bands were dead and the SWR was through the roof. I later observed the antenna it was hooked to had the coax separate from the center insulator. Using another antenna it seems to be OK, except I got a terrible report from DK5DR on SSB but later got a fine report from a PA3 and it sounded ok on my KX3.
When I ran 1.38 last month on my laptop I got the same exception error so my laptop has not been used on my Flex. The virus, malware was disabled. I have had errors on my hard drive in the last few months. I also can't get Team viewer to run on the laptop.