I can't do sudo apt-get update; when I try it gives me loads of failed to fetch everything. I have no idea what could be wrong. I searched for what the sources.list file should look like and it looks the same to me.
Err http://nl.archive.ubuntu.com vivid InRelease
Err http://nl.archive.ubuntu.com vivid-updates InRelease
Err http://nl.archive.ubuntu.com vivid-backports InRelease
Err http://nl.security.ubuntu.com vivid InRelease
Err http://security.ubuntu.com vivid-security InRelease
Err http://archive.canonical.com vivid InRelease
Err http://nl.security.ubuntu.com vivid Release.gpg Temporary failure resolving 'nl.security.ubuntu.com' Err http://security.ubuntu.com vivid-security Release.gpg Temporary failure resolving 'security.ubuntu.com' Err http://archive.canonical.com vivid Release.gpg Temporary failure resolving 'archive.canonical.com' Err http://nl.archive.ubuntu.com vivid Release.gpg Temporary failure resolving 'nl.archive.ubuntu.com' Err http://nl.archive.ubuntu.com vivid-updates Release.gpg Temporary failure resolving 'nl.archive.ubuntu.com' Err http://nl.archive.ubuntu.com vivid-backports Release.gpg Temporary failure resolving 'nl.archive.ubuntu.com' Reading package lists... Done W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid/InRelease
W: Failed to fetch http://nl.security.ubuntu.com/ubuntu/dists/dists/vivid/InRelease
W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid-updates/InRelease
W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/vivid-backports/InRelease
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/vivid-security/InRelease
W: Failed to fetch http://archive.canonical.com/ubuntu/dists/vivid/InRelease
W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid/Release.gpg Temporary failure resolving 'nl.archive.ubuntu.com'
W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid-updates/Release.gpg Temporary failure resolving 'nl.archive.ubuntu.com'
W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/vivid-backports/Release.gpg Temporary failure resolving 'nl.archive.ubuntu.com'
W: Failed to fetch http://nl.security.ubuntu.com/ubuntu/dists/dists/vivid/Release.gpg Temporary failure resolving 'nl.security.ubuntu.com'
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/vivid-security/Release.gpg Temporary failure resolving 'security.ubuntu.com'
W: Failed to fetch http://archive.canonical.com/ubuntu/dists/vivid/Release.gpg Temporary failure resolving 'archive.canonical.com'
W: Some index files failed to download. They have been ignored, or old ones used instead..
