18.04 update is not found from ubuntu 17.10

[dilitherange]

I want to upgrade my Ubuntu 17.10 to 18.04 LTS But when i issue update-manager -c command it says

Software updates are no longer supported for 17.04 update to 17.10

When i click upgrade 17.10 upgrader pops up. After few seconds it says,

Software is upto date, no upgrades are available for this system

I'm sure that i have 17.10 not 17.04.
Setting>details also shows 17.10

I also tried do-release upgrade command but it not work.
I have tried
root# apt update
root# apt upgrade
root# dist-upgrade
root# apt-get autoremove
root# install update-manager-core
root# do-release-upgrade

[deadflowr]

What are the actual output for all those commands you posted?

[dilitherange]

All the commands says up to date.
do-release upgrade tries to upgrade to 17.10 even though my version is 17.10. But update is not work

[deadflowr]

What do

lsb_release -a
grep Prompt /etc/update-manager/release-upgrades

show?
Post the outputs.

[dilitherange]

lsb_release -a
output:

No LSB modules are available.Distributor ID: Ubuntu
Description: Ubuntu 17.04
Release: 17.04
Codename: zesty

grep Prompt /etc/update-manager/release-upgrades
output:

Prompt=normal

[Impavidus]

The output from

audo apt-get update

might tell us more, like which repositories you try to use.

Anyway, it looks like you either run 17.04 or a broken 17.10 and in both cases a fresh install of 18.04 would be a better idea than a release upgrade.

[dilitherange]

The output from

audo apt-get update

might tell us more, like which repositories you try to use.

Anyway, it looks like you either run 17.04 or a broken 17.10 and in both cases a fresh install of 18.04 would be a better idea than a release upgrade.

I'm pretty sure that my version is 17.10 because i installed using 17.10 iso

This is the output of sudo apt-get update

Get:1 http://security.ubuntu.com/ubuntu artful-security InRelease [83.2 kB] Hit:2 http://lk.archive.ubuntu.com/ubuntu artful InRelease
Get:3 http://lk.archive.ubuntu.com/ubuntu artful-updates InRelease [88.7 kB]
Get:4 http://security.ubuntu.com/ubuntu artful-security/main amd64 DEP-11 Metadata [32.7 kB]
Get:5 http://lk.archive.ubuntu.com/ubuntu artful-backports InRelease [74.6 kB]
Get:6 http://security.ubuntu.com/ubuntu artful-security/main DEP-11 64x64 Icons [37.0 kB]
Get:7 http://security.ubuntu.com/ubuntu artful-security/universe amd64 DEP-11 Metadata [40.3 kB]
Get:8 http://security.ubuntu.com/ubuntu artful-security/universe DEP-11 64x64 Icons [44.8 kB]
Get:9 http://lk.archive.ubuntu.com/ubuntu artful-updates/main amd64 DEP-11 Metadata [88.4 kB]
Get:10 http://lk.archive.ubuntu.com/ubuntu artful-updates/main DEP-11 64x64 Icons [50.0 kB]
Get:11 http://lk.archive.ubuntu.com/ubuntu artful-updates/universe amd64 DEP-11 Metadata [84.7 kB]
Get:12 http://lk.archive.ubuntu.com/ubuntu artful-updates/universe DEP-11 64x64 Icons [111 kB]
Get:13 http://lk.archive.ubuntu.com/ubuntu artful-updates/multiverse amd64 DEP-11 Metadata [2,468 B]
Get:14 http://lk.archive.ubuntu.com/ubuntu artful-backports/universe amd64 DEP-11 Metadata [5,088 B]
Fetched 743 kB in 13s (53.7 kB/s)
Reading package lists... Done

[deadflowr]

Was this a fresh install over 17.04?
(Meaning it was 17.04 but then you tried a clean install of 17.10 on top of it?)

[dilitherange]

Was this a fresh install over 17.04?
(Meaning it was 17.04 but then you tried a clean install of 17.10 on top of it?)

I installed from fresh 17.10 iso

[mIk3_08]

I installed from fresh 17.10 iso

Just a question, where did you download your fresh 17.10 iso? Because you should ONLY download Ubuntu from the Ubuntu website;

https://www.ubuntu.com/download

and for alternatives
https://www.ubuntu.com/download/alternative-downloads
I prefer you should download with the LTS (Long Term Support)

Because if you got it from anywhere else, there is a possibility that it may have been modified and have some malware where it was redirected or can't get into an upgrade.