getting user account for security in MS SQL

select PARSENAME(REPLACE(SUSER_NAME(), '\', '.'), 1)

select SUSER_NAME()

Remote Server Administration Tools for Vista

http://www.trainsignaltraining.com/windows-vista-rsat/2008-04-03/

Installing Remote Server Administration Tools for Vista
There are two versions of the RSAT tool, one for 32-bit machines and one for 64-bit machines. You can download the version you need at their respective download locations:
Download: Remote Server Administration Tools (x86)
Download: Remote Server Administration Tools (x64)

http://www.microsoft.com/downloads/details.aspx?FamilyId=9FF6E897-23CE-4A36-B7FC-D52065DE9960&displaylang=en
http://www.microsoft.com/downloads/details.aspx?FamilyId=D647A60B-63FD-4AC5-9243-BD3C497D2BC5&displaylang=en