This is what concerns me about your first post:
If you format any partition you will loose all data (including an OS) that is on it. But if you want to do it your way and if you only want Windows 7 on that hard disk, then by all means just re-install Windows 7.Now, how do I format the other partitions so that it boots properly into the fixed windows 7 OS partition?
If its not booting properly then may be a re-install is the only answer. But without knowledge of the error messages that you get when trying to load Windows 7 and knowledge of any other OS that you may or may not have. I do not think that it would be wise to give you exact advice.