Most methods, when done correctly, will retain everything. But if it asks "do you want to keep your apps and data" and you answer "no", they will be gone.
I am running Windows 7 Pro 64 Bit on my desktop. I have seen numerous blogs about the free upgrade to Windows 10 still being available. My question is if I use the method outlined in these blogs will all my applications and data files be retained or will the upgrade be equivalent to a clean install?

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