>>>I am about to download and install SQL Server 2008 express on customer server. I found MS page that seems to be the right one ( http://www.microsoft.com/en-us/download/details.aspx?id=23650 ). But what makes me wonder if I am on the right page is that it says the date published is 04/20/2010. Didn't MS have a more recent version of SQL Server 2008 R2 (not 2012)?
>>
>>http://www.microsoft.com/en-us/download/details.aspx?id=30438
>
>Thank you. I see that for 64-bit there are three files:
>SQLEXPR_x64_ENU.exe
>SQLEXPRADV_x64_ENU.exe
>SQLEXPRWT_x64_ENU.exe
>
>The customer server is 2008 64-bit. Do I understand correctly that I need to use the top choice file above?

I think you may want at least WT (with tools) or ADV (advanced services). If you download the first one, you will not have SSMS.

So, it depends, but if you need to manage this instance from that server you need SSMS.