Network File Sharing Between Windows 7 & Vista

i got 2 laptops one vista and one windows 7 connected on my home network, now on the windows 7 laptop i can connect browse and copy files no problem from the vista laptop to my 7 laptop, but when i try to copy from my 7 laptop on my vista laptop it asks for a username and password.

on my windows 7 laptop it doesnt ask me for a name or password at all. What is the username and password im suppose to use? i use the password and name that i use when the computer locks up but that doesnt work how can i disable this on the vista laptop so i can connect and copy files over my network with out needing a password?