Every time I try to log into SL with the regular 2.0 viewer.. my internet goes out?

[Cy Innovia]

The internet is usually pretty strong any time else.. but it just turns as soon as I click log in.

Is there any settings I can check to find out what's going wrong?

[Rolig Loon]

It could be any one of several issues.  If it's not letting you in at all, consider the possibility of a firewall block.  Read at https://wiki.secondlife.com/wiki/Configuring_your_firewall and th embedded links to see what you can do about it.  If you are able to log in but crash almost immediately afterwards, try logging in to a quiet sim instead to see if it helps.  Smith, Pooley, and Aqua are essentially vacant, so they're good places to try.  

Among the many other possibilities ...... You could have an unstable Internet connection --- stable enough for normal web browsing but not for the continuous streaming that SL demands.  Try rebooting your router and modem by unplugging both for a few minutes.  When you reconnect, they'll grab a fresh IP address.  Also, check the router itself to be sure that its drivers are up to date (and that the router itself isn't just too old.  I replaced my 4-year-old router a year ago and was amazed at the increase in stability.).  You can also check for packet loss -- another potential network issue that can mess up SL -- by following the advice at https://wiki.secondlife.com/wiki/How_do_I_check_for_packet_loss_%28network_lag%29 .