Hello, not sure if this is the right place for this question, feel free to move it!

I run Lubuntu but wanted to install Windows. So I used GParted Live CD to shrink the Linux partition and create a new Windows partition. Then I installed Windows on that partition fine and it boots. Then to get back into Lubuntu I used GParted to change the boot flag from the Windows partition to the Linux partition, but now it won't boot and says Error loading Operating System. Help?