get win 10 home serial key & Install Dell Support Partition

By mistake I have deleted all my partition with Alienware recovery bootable now I have new  windows 10 Home and only one partition Dell support Recovery and Image Partitoin on Alienware 15 R3  are deleted.But I dont know how to activate my windows cause I did not get win serial Key with my laptop. How to get this Product ID?

2- Is there any way to install "Dell support" and Recovery Partition as a bootable partition again?

Thank you in advanced.