Yes, be sure to disconnect the HDD drive from the PC before installing Windows on the SSD. After the install you will be able to plug the HDD back in and use it normally.
If the HDD is connected during installation, the Windows installer will force-create backup partitons on the HDD drive, which might compromise some of the data.
Is there anything I need to do after I connect it back or will it read it automatically?
(sorry for bothering you I just never did anything like this before even though I have built some pcs including mine)