Why is it still possible to recover files that have been emptied from the Recycle Bin on a Windows computer?

One technique for hiding information is to change the file extension from the correct one to the one that might not be noticed by an investigator. For example, changing a .jpg extension to a .doc extension so that a picture file appears to be a document. What can an investigator examine to verify that a file has the correct extension?

For what purpose do the investigators use tools like iPhoneBrowser, iFunBox, OpenSSHSSH, and iMazing?

Which program is the bootloader when Windows XP starts up?

Which U.S. law sets the rules for sending emails for commercial purposes, establishes the minimum requirements for commercial messaging, gives the recipients of emails the right to ask the senders to stop emailing them, and spells out the penalties in case the above said rules are violated?