I have a question for you PC builders and tech savvy's?

I have Windows 7 installed on my current CPU and a friend is giving me a better one that fits my motherboard with Windows 10 on it, plus better RAM sticks. If I place his CPU into my motherboard what can I expect to see? Will my desktop look different? Will sticky notes and other apps still be displayed? Or will I have to redownload those things? I might have some sensitive things displayed on my desktop that I wouldn't want him to see. Thanks!