So I try to `apt-get update` on the regular when I am working in Terminal. Recently I have been running said command and getting a few errors at the end. Doesn't seem to effect my box to much of an extent but, how can I go about troubleshooting all of these issues that are being returned? See below: 

```
W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/main/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/restricted/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/main/binary-i386/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/restricted/binary-i386/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch htp://ppa.launchpad.net/ronmi/wallbox/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found
W: Failed to fetch htp://ppa.launchpad.net/ronmi/wallbox/ubuntu/dists/trusty/main/binary-i386/Packages  404  Not Found
W: Failed to fetch htp://ppa.launchpad.net/versable/elementary-update/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found
W: Failed to fetch htp://ppa.launchpad.net/versable/elementary-update/ubuntu/dists/trusty/main/binary-i386/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.

```