Accessing linux partition on dual boot laptop

I've been having trouble accessing the linux partition on my laptop. I had to reformat my windows partition, and after I did I lost access to the linux partition.

The partition is still There, it shows that all the data is still there in the partition, but I can't get into it. All my music, pictures and documents are still on the linux partition.

I don't know how to make the option come back when I turn on my laptop for me to choose if I want windows or linux to boot. Can anyone give me some advice?