MCS Electronics has a web shop and forum that requires a username and password.
There is also the register which is used for updates. This is separated because you need to be able to update when you purchased from a reseller.
This register also requires a username and password. You can chose them yourself.
Both account need an email address. This is done for security. When you create an account, the system will email you a message with an activation link. You need to click the link to activate your account. Without this, your account is invalid.
This is done to prevent spam. And you also know that your email is correct when you receive the activation email.
When you forget your password you can ask the system to send you a new password. The system will send it to the known email address.
For this reason it is important that you keep your email up to date.
So when you got a new email address, update it in the system.
The system will not send to an address you provide, this to prevent spam. This also means that it is important that you keep your account name and password stored at a secure place.
When your email address changed, and you lost your password as well, you cannot update the system and the system cannot send emails to your new email address.