Share between WinXP and Win7

Here is my situation

- I have two computers: one on Win7 and the other one on WinXP
- File sharing is working perfectly between my Win7 PC and another Win 7 PC
- File sharing is also configured on Win XP PC and is working with another Win XP PC
- I can access winXP shares from my Win7 PC
- On winXP PC, i can see win7 computer on the network but i can't access the shares !

The problem is that i can't access Win7 shares from my winXP PC. I get an error saying i may not have the right to access it

I googled the problem and tryed many solutions, but nothing works

of course, i already tryed everything suggested here:
http://www.tomshardware.com/forum/ [...] a-machines

HELP !

ok i just got it, i really need to turn off password protection

but the problem is that i'm sharing network with my neighboor, and i dont want him to access my shares

so is there a way for my WinXP pc to access the Win7 shares with a password ?

thanks

if you want to share a few small files you can use a cloud service like dropbox or microsoft skydrive.