When are you prompted? Without specifics, I assume it is when you are filling in the account information (e.g., email id, server, etc), in which case it would be the account password. It is possible to have a primary password, but that can only be set after installation and must be initiated by the user. Since you mention you are trying to install, yet there are already passwords there, more information is needed.

After download of the program, I am prompted for my name, email an password. Just at the beginning

Okay, that's the process of gathering information to set up your account. If it's for GMAIL, leave password blank. (it's a long story...)

No, n ot gmail, Belgian provider Telenet