When I'm clicking on the check button, after a few seconds it' showing the following
W:Failed to fetch gzip:/var/lib/apt/lists/partial/us.archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_binary-i386_Packages Hash Sum mismatch
, W:Failed to fetch copy:/var/lib/apt/lists/partial/us.archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_i18n_Translation-en Encountered a section with no Package: header
, E:Some index files failed to download. They have been ignored, or old ones used instead.
I can't solve this problem. Please anyone help me.