VNCViewer from old (windows)computer to new (windows) computer

Dear People,

i worked with vnc viewer for a couple of months now, it works perfect on my old laptop.

now i installed VNC viewer on my new Laptop logged in with my acount and tried to connect to on of the 3 servers that i used before. with all 3 of them i get the message that or username was not correct or the password was not correct.

the viewer still works nice on the old one, probably got to do with the new "name' for my new computer.

tried several things, looked at the community but could not find what tot do.

does anybody know how to fix it