Windows bypass any security when reinstalling from USB?

Solution 1:

There is no defense against a knowledgeable person that has a physical access to your computer. There are so many ways to access your data by booting a malicious USB.

Your only possible defense is to either disable USB in the BIOS and place a BIOS password, or to install a physical padlock on the computer. None of which is a pretty good solution.

If there is some particular data that you would like to keep safe, encryption is the best method. See for example VeraCrypt. Bitlocker was also mentioned in a comment.

Be very careful when encrypting to properly save the encryption and recovery keys, to be sure of getting to your data in case of a catastrophic failure.