Cancel it. Restart your router, restart your PC, and run the tool as Administrator. Something is wrong.
You likely have a failing hard drive or a virus. Stop trying to download Windows and run a disk check first.
So, you’ve finally decided to upgrade to Windows 10 or perform a fresh installation. You click the "Download" button on Microsoft’s website, sit back, and wait.
But 30 minutes later? You’re still staring at a progress bar.