Visual Studio - Error: Unable to download installation files
You can try these steps:
First, make sure that you use administrator account to log on to the PC and your Internet can access any websites.
delete the Installer folder under C:\Program Files (x86)\Microsoft Visual Studio\
Right-click on the vs_xxxxx_xxxx.exe(installer program)-->Properties-->Digital Signatures-->you can see "signature list"-->Select signature and then Click on Details button-->Click on View certificate button--> Click on Install certificate and follows installation wizard.
Fire up Run, type gpedit.msc
Brows to the following location: Computer Configuration-->Administrative Templates-->System-->Internet Communication Management-->Internet Communication settings then find the entry Turn off Automatic Root Certificates Update and open her up and set it to Disabled.
Get Windows to check for updates and if so, update it.
Then run the installer as administrator to install it.
In addition, if you create an offline installation, please use like this:(remember to add --lang en-us)
vs_community.exe --layout C:\vs2019offline --lang en-us
Besides, when you finish it, please install the three certificates as administrator which are in the certificates folder of the offline package and after that, install the installer.
Also, make sure that these certificates are in the trusted folder.