Are there alternate DNS servers I can use ?
Since many connectivity issues are eventually traced to DNS problems, you can add to, or even replace your ISP's nameservers with other public ones.
One of the better alternatives is to use Google DNS, just configure your network adapter to use the following IP addresses as your DNS servers:
More info on Google DNS can be found -here-.
Here are some other free public DNS servers you can use:
OpenDNS (uses 12+ different global data centers):
There are other alternatives to the US government DNS root zone, which cover some new TLD listings that many nameservers don't yet include. Check here for more information: Alternative DNS root.
Note: It is a good idea to choose a DNS server that is geographically close to you