This question is an exact duplicate of:
I don't know if I'm the only person to find this out or not. But anyways I like the way wubi works so I was kind of mad that 13.04 didn't have it. But I was playing around, and I downloaded the Ubuntu 13.04 iso file and I extracted it to a folder, and surely enough after I extracted it, I went to that folder and in that folder I found awubi.exe so I double clicked it and it worked! Now I'm running Ubuntu 13.04 off of a wubi install and it works perfectly fine for me. This shocked me because I thought they had gotten rid of wubi installs after 12.04 but I guess it's still possible. I thought I would just share this with everybody.