Problem accessing my private proxies

I'll keep this short: so I bought a few private proxies and I've been using Elite Proxy Switcher for other shared proxies before I got these new private ones. However, when I go to any website on my browser it tells me to enter in my username+ password, I do so, exactly as they were given to me (I've tried typing them by hand and copying+pasting them) and the box closes but then a new one opens up and I can't go to any websites and eventually a cache message comes up from the browser. Is it the Elite Proxy Switcher causing this? I'm pretty new to the world of proxies so am I supposed to enter the proxy's IP+port somewhere into my computer?

Hi,

Have you checked that there are no whitespaces before or behind your data?
Try the addon foxyproxy in Firefox for easy testing.

hi,

your proxies are with user and pass. To get rid of that annoying popup which request them you need to contact your proxy provider and ask them do provide you IP based auth.

That will allow you to connect from your IP without any user and pass

And also try to check if the IP is still working, if it's dead you are most likely going to experience the same situation and box opening up prompting for username and password.