I’m trying to upgrade to 2017.1, a message asked me if I want to run the Unity download assistant. I think I should click yes, but a warning said that the file might harm my computer. I’m using a windows computer. How could it harm my computer (in what way), and how do I know if it will or will not harm my computer?
Screenshot?
This is more than likely due to your security settings; it is normal when you attempt to download and run a .exe file from the internet this warning is displayed.
Any executable file could harm your computer (unless you wrote the software yourself and knew exactly what it was going to do). It could rewrite your registry, format your harddrive, harvest your passwords, or transfer money from your online bank account.
But, assuming you only ever download software from a reputable source (i.e. only download Unity files from the unity3d.com website) you can be relatively assured that it won’t do anything nefarious.