Sxt lite 5 unable to update router os

RouterOS Beginner Basics
1

Sxt lite 5 router is ver 6.34.2 I had install i n my router is manually. But if I am going to upgrade latest is through the option in my router is .it was not detect automatically newest version.
Help need

2

6.34.2 is already the latest version. there is no newer version
Screenshot 2016-03-01 11.38.18.png

3

But before that latest version it was in 5.26.and I update it manually sir.it was not able to update automatic .err msg show could not solve DNS server

4

It means you have no internet. Check settings in “IP address” and “IP DNS” menus.

5

The device itself is unable to resolve the Mikrotik update server hostname. If you don’t obtain your IP address information automatically through DHCP, check that you have set up a DNS server within the Mikrotik RouterOS

.err msg show could not solve DNS

shows that the router cannot resolve properly.

Example:

/ip dns
set servers=8.8.8.8,8.8.4.4
6

Now I want to clear every setting.want my device in default