It is very hard to understand what might be happening in some circumstances with dual boot installs. Hopefully the Startup repair Drew suggested will work, but it appears when you "wiped" the drive, you removed the boot files. This can be fixed, but if the Startup repair does not work after 2 or 3 subsequent trys, you may need other help. Perhaps just making the Win 7 partition active might allow the Startup repair to work.