First your windows 7 starter won't run windows server 2008. It requires a separate computer with the capabilities of server 2008. Additionally, your starter version of windows 7 will run the rdp program to connect to another computer running server 2008 or windows 7 pro and above.
the rdp program for your version of windows is located at %windir%\system32\mstsc.exe
Windows server 2008 will run on a Virtual drive on computers that are capable of running the virtual machine from mS or other Virtual box people.
What you download with server 2008r2 is an .iso that you can then create a dvd or mount it under a virtual operaing system. but not on windows 7 starter..