It sounds like a dns issue. Try using the nslookup
command from a command prompt or "ping" to see if you can
look up other sites by name
e.g nslookup www.google.com .If it can't do this, check
your dns settings for your LAN/dial up connection or
check with your isp that you have the right settings and
that there DNS service is working properly

Type ipconfig /all at the command prompt to see which dns
servers you are using.

www.microsoft.com I get the error "Unable to resolve
target system name www.microsoft.com.