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#11
Hello again Adrian.
No mate, it's not necessary at all, you can just leave everything connected and you will get the Windows managed dual boot as mickey megabyte mentioned earlier and all will be fine and you still won't need a third party boot manager.
You could just format the Vista partition during install and do the install there with no issues.
I would give serious consideration to this though using the outline in Step Two #3 to create the new Windows 7 "System Reserved" partition and a 100GB partition to install the 'new' Windows to; this will make the new SysResv partition the system volume making it very easy to remove the 'old' Windows when the time comes.