http or https?

I think I have upped my security and now get warnings for various websites saying their certificate isn't secure. One of them is the mylotto website....

On some pages the padlock at the top is locked, so what do i need to do to change whether I am viewing https or http websites?

many thanks

Which browser are you using?

Sent from my GT-I9300 using Tapatalk 2

Internet explorer (yep sorry should have said).

https is supposed to mean a secure site, the warning your getting just means the security certificate is expired or not recognised, it's very common & doesn't make the site any less secure. They just warn you because hackers can BS a security (https) certificate when trying to scam you, so long as you trust the site don't pay too much attention the the warnings.
As for choosing between the 2 it's as simple as https/www.somewebsite.com vs http/www.somewebsite.com
But remember "https" is theoretically always the secure one (encrypts data)

How do I change it back though to accept http without going through the warnings?