If you want to block the Roblox website or app, or prevent Roblox from being downloaded on your Windows 11/10 computer, see this post.

Here's the trick to appear Offline on Roblox on your Windows PC or Mobile Phone and prevent users from communicating with you.

Now Roblox should have no problem installing on your PC! In the event it doesn’t, double-check that you don’t already have Roblox installed and, if so, remove it for a fresh installation.