SQL Server Managment Studio R2 2008 on Windows 8 64-bit problem

[Radient]

Hey, i am not so new to this community, i have done this many times but only on windows 7(installed SQL 2005 but this time its 2008 decided to upgrade :P), and now i installed windows 8 and i installed sucssesfully but when i want to connect to the sql server i simply cant, i dont know my host name, ik the host name is supposed to be USER-PC\SQLEXPRESS
but i tried that with the user name sa and my password, but it doesnt work, do you have any ideas? thanks for the helpers :)

[MentaL]