No need to erase partition before installing. Just pop in the disc, it will prompt you at some point where you want to install winblows and will format or create partition at that time...
BTW, I haven't done this in a while so I may not be 100% accurate
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'07 997.1 GT3
'08 E90 M3
'11 E90 d
'02 Rota Grid - 195-55-16FR (RIP)
'04 Volk GTC - 245-35-19F/275-35-19R (Sold to a farm boi)
I thought Spark was a robot from the old movie and I kind of remember seeing him telling some engineer showing the equation for a clear metal that the guy would event years later - porschetr