Where does firefox store my Profile?!

i tried this from Mozilla support:-
1. Click the Windows Start button and type %APPDATA%\Mozilla\Firefox\Profiles\
in the Search box at the bottom of the Start menu, without pressing Enter.
2. A list of profiles will appear at the top of the Start menu.
Click on the profile with “default” in the name to open it in a window.

but it didn't work, when i copied this file to another laptop (W.XP) it didn't work,
PLEASE HELP! i can't start my W.7 & i'am trying to copy all of my data to this laptop
(W.XP) but the only thing that didn't work is this program.

In W7 Firefox stores it profile in

C:\Users\[User name]\AppData\Roaming\Mozilla\Firefox\Profiles

In XP copy the default profile to:

C:\Documents and Settings\[User name]\Application Data\Mozilla\Firefox\Profiles

thank you, but sense i copied the folder this error message shows to me.
i tried to close firefox & restart but nothing works with me=>

You should delete the old profile and replace it with the newer one
Reinstalling Firefox should fix the problem

THAAAAAAAAANK you very much sir.