Hi
Central services instance for ABAP & JAVA installation on the virtual host? have you started the SAPINST from Command prompt?
(eg sapinst.exe SAPINST_USE_HOSTNAME=<Cluster Virtual host name>)
and better use the Sap installation media NW7.0 SR3 (Not NW 7 SR1)
refer the sap installation Master guide
Thanks
Sriram