Just as the topic says. My Mid 2010 iMac has been having some issues and I just went through disk utility and I found out that my Macintosh HD was corrupt and needs to be repaired. It says it needs to be repaired but the 'repair disk' button isn't clickable. I can't figure out how to start with my installation disc because there is no installation disc for Lion. I tried with my Snow Leopard disc and it didn't work. Below is a screen shot of what my disc utility looks like when I try to verify disc.