i am finding problem at the last phase of installation.
Unable to open RFC connection
This is not a error your installation Finished but at the end Phase it start the SAP and do the connectivity with it through RFC Connection and your system is not very fast due to that SAP was not able to connect to the SAP Management Control that's why it gives error
Just OPEN the SAP Microsoft Management Console and start the SAP and when SAP get start then only click on retry Buton..
and within few min SAP installation Get Finished.