this application has requested the runtime to terminate it in an unusual way windows 7

Hi all, I recently created a program using qt 5.1.0 on windows 8. After getting the release build compiled and stacking together the dlls, i got it working perfectly on my windows 8 machine. However, when I try to send it to my friends and family on windows machines 7 and below, it doesnt work at all, and displays this message instead: “this application has requested the runtime to terminate it in an unusual way…” Honestly, im kinda stumped on what to do here. I assume there is something about the way its compiling, or perhaps its the project file, but nothing comes to mind yet. Is there any way to tell what’s causing this, or better yet, is there a way to fix this? Thank you in advance ps. lemme know if i need to share more info on the subject