I used Windows 10 Media Creation Tool to download the ISO file for Windows 10 Pro 32-bit. I used it to update Windows 8.1 Pro on a laptop. The installation went fine.

Later on another computer with Windows 7 Ult 64-bit I decided to burn the ISO to a DVD using Nero 9. I tried two different DVDs but got verification errors for both of them. Anyone have any idea why this is happening?

Also, I downloaded several different ISO files because I have other computers to upgrade to Windows 10. I want to make sure these ISO files are OK but have not seen any published checksums so I can verify them. Below are the SHA-1 values I get:
8aeb94384ea0edef75a719fa0c19d64a4f235b2d, Windows10Home32.iso
6fe824535a2caee2f48023636c97d398583ffb53, Windows10Home64.iso
5d7530f09d07c43bd648edbb5a9cd10cd0a8ccb1, Windows10Pro32.iso
494bbd41032ad928d4dfa0d4dee1f3ffb1ae2380, Windows10Pro64.iso