If you happen to have another HDD, you could install (or use) windows on it and try recovering the data on the first HDD by using a program like Recuva or EaseUS.
I'd recommend this if possible; for since you're installing/using windows to a different HDD, you aren't writing anything to the first. Then, after you've gotten the data off, you could wipe the first drive, install windows, and put the data back on.
First, I'd try using Recuva. I'm not sure if it'd work in this case, but it's very reputable. If it doesn't work, you could try EaseUS Recovery. I haven't used it, but it seems specifically made to do this type of thing.
