Dual boot RHEL 7 Server and Windows Server 2008 R2

Windows Server 2008 R2 was installed on my server.
I shrink some space for RHEL 7 and installed it there.
Windows partition was not affected, however boot-loader doesn't offer to start Windows.

How to configure dual-boot of RHEL 7 Server and Windows Server 2008 R2? Should I do something during RHEL 7 installation or after RHEL 7 is installed?

I don't know if this is important, but I'm using RAID - Smart Array P420i on HP DL360p Gen8 646902-421. Attaching my current disk layout.