I can provide you this as I have used the installer for both google chrome and firefox and both come up with a "Do you want to allow scripts to run" message at which I click yes (and have alos clicked no) to proceed with install. ON BOTH installs (and when clicking no) the installer fails with one word: undefined.
I suggest you look at it instead of asking silly questions.
EDIT: Once the installer quits the .exe that is downloaded is auto deleted by itself!!!! Acting more like a virus than a trusted program if you ask me.
The online installer, which you are using, is a shim installer that downloads and installs Flash Player silently in the background, and is designed to delete itself after it is executed.
Regarding the script error, the online installer team has investigated this and identified the DPI setting as the culprit. If the DPI setting is not set to 100%, 125%, 150%, or 200% the installer will return the script error. If your DPI setting is set to something else, please set it to one of these and the online installer should work. The team is working on a fix for this.
To check/modify the DPI setting:
1. Launch Control Panel and navigate to Control Panel\All Control Panel Items\Display
2. In the left menu, select Set custom text size (DPI)
3. In the Custom DPI Setting windows select 100%, 125%, 150%, or 200% from the drop down menu
4. Select OK
5. Select Apply
6. Log off/on
7. Online installer should now work without displaying the script error.