For help, refer to this article:

Using The Profile Manager

You might find this KB article helpful, too.
http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox

yes,but how can i make that firefox use x profile and aurora use y profile?

That is explained here:
http://kb.mozillazine.org/Starting_your_Mozilla_application_with_a_specified_profile

ok.i go to the command line argument [windows-run] and what do i need to write there? the profile name? do it when aurora is open?

wow ok thx!! i understand. one little more question can i remove the old shortcut?

all works but now i have another problem:when i want to update aurora it says: update could not be installed Please make sure there are no other copies of Firefox running on your computer what can i do?

Forget using the command line in the Windows -> Run box, you'd have to type there each time. Assuming that you created a desktop shortcut already, try something like this in the Target line of a Firefox desktop shortcut

"C:\Program Files\Mozilla\Aurora 25\firefox.exe" -p "Profile Name"

You would need to add a space -p another space and then the name of the new Profile, to what automatically appears in the Target line.

Example is here- http://kb.mozillazine.org/Shortcut_to_a_specific_profile , which was linked from both page that I hyperlinked before.

THX! About the update in aurora its all works now. but i downloaded aurora in 8/19 and i check for update and i have an update. It's every time updated like that? day after day? [I promise you-this is the last question]

Yes, Aurora receives daily updates, when there is a "check-in" of new or changed code from the last time Aurora was "built". After all, it is an alpha development version, but 6 weeks advanced in the development stage from the Nightly builds on the same day.

Every new Firefox version spends 6 weeks in the Nightly channel, then 6 weeks in Aurora, followed by 6 weeks in Beta before becoming the new Release version.

ok. thank you very much!

Firefox on the Aurora channel stops updating for a few days when a new Firefox version is released to allow the tree to stabilize when moving to the next Aurora version.

The Beta version currently gets two updates a week apart from the first week (week 1) and last week (week 6) when only one update is released.