I can't boot into my windows after resizing my partition
I'm running OS X 10.10.3 & Windows 7 Home Premium x64
iMac 27 Inch Late 2012 model
I need more space on my windows partition so i decreased the size of my mac partition from 800gb to 675. After this was done i was going to boot into my windows partition and expand it using minitool wizard. I tried this once before and it worked fine but this time my windows partition disappeared once i decreased the size of my mac partition. I did this without backing up any of my windows files and i now i'm worried they might be lost. I tried to fix it using this information i found in this threadI can't boot to Windows after resizing my Mac partition.
I tried some commands in terminal and now the windows partition shows up once i re boot and use the option key but it says the operating system is missing. I had some really important files on my windows partition and i might not be able to replace them. Is there any way i can i get it back to normal ? I apologize if my post lacks detail it's just that i'm not really good at solving issues like these.
iMac (27-inch, Late 2012), Mac OS X (10.1.x)