Ok I understand but I don't know that I have to do yet... :-(
My %APPDATA%\postgresql\pgpass.conf file is ok
No it isn't otherwise you almost certainly wouldn't get the error... unless the connection string you installed pgAgent with is incorrect.
If you email the pgpass.conf file across (with the actual passwords replaced with XXX or something, and include the pgAgent command line I'll check it.
Regards Dave