Linux – Allowing multiple passwords attached to one account (Linux)

The other consequence, is that your account can be used to connect to the computer over the network. By default, Windows XP (and later), accounts with no password cannot be used to access the computer from the network. So it closes off any external attacks; in that way it is better than an account with a weak password.

For that reason it is sometimes recommended to have user accounts with no password at all.

As for why I can see a number of reasons:

1. Windows XP was the transition for mainstream users from Win 9x that didn't have any passwords.
2. Some people could be confused by having a password (or the whole idea of accounts), forgetting the password, etc.
3. The computer doesn't need a password. That is there is nothing important enough to protect. (And due to the network lockout, it can only be accessed physically. If that's a home machine it means that the attacker is already in your house)

Resetting the password doesn't wipe user data.

The influence is limited only to a part of data that has increased protection, like encryption keys to the files that were encrypted with EFS (separate from Bitlocker, i.e. through file properties, General, Advanced, "Encrypt contents to secure data"), personal certificates, and stored passwords.

If you have a usable local administrator account (which you imply you have) you can just open Computer Management -> Local Users and Computers, right-click on the user (self) and select "Set password" option. You should not be asked for the current password.

For your individual case, if you are helping someone, the best procedure would be to backup the data or clone the disk with Clonezilla, and perform the password reset.