al08,
You DO need to establish a username and password for this device to connect to your DSL service. Your DSL ISP should have given you this information. Generally, it's your email username and password but I can't say this is a rule of all DSL providers.
Check out:
ftp://ftp.dlink.co.uk/dsl_routers_mo...ig_english.pdf
Go to Page 7 and see if this helps. Otherwise, you really need to contact your ISP's tech support.
- John