I would only recommend installing Ubuntu and Windows 7 on the same machine if Ubuntu was the last OS installed in the chain. You always want to put the OSes with the most complex bootloaders at the end so, for example, Windows XP would come first, Vista/7 would come second, then Linux.
I suggest wiping Ubuntu and starting over.
Here's what you need to do:
1) Install InfraRecorder:
http://infrarecorder.org/
2) Hit "write image"
3) Select your Windows 7 ISO
4) Wait
5) ???
6) Done
7) Install Windows 7