No, it won't wipe both drives unless you tell it to. But in situations like this, I sometimes find it better to just disconnect the second drive during the install, and then reconnecting it later. Then there's no chance you can accidentally wipe out anything on that drive.
Hi,
I am upgrading to Windows 7 and I have two HDD's in my computer. When I upgrade (using the clean install) will the installation wipe out both of my HDD's and then install just to my C: drive? Please let me know.

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