After installing, you can in theory remove a password with:
ALTER LOGIN sa WITH PASSWORD = ''
I can't test this because in my environment Windows won't let me have a
blank password and SQL Server is using the Windows policy.
(Legal disclaimer: Please do not take this posting as a recommendation that
you should do this.)
--
Rick Byham, MS
This posting is provided "AS IS" with no warranties, and confers no rights.

"Andrea Montanari" <andrea.sqlDMO@virgilio.it> wrote in message
news:4nf9roFa36k5U1@individual.net...
> hi,
> Italstudio S.p.A. wrote:
>> I need this only for testing purpose.
>> Does anyone know how I can do this???
>
> you already heared it' not recommended and I will not bore you once
> again about it
>
> BTW, bol states: "In order to rebuild system databases, a new System
> Administrator (sa) password is REQUIRED. Do not use a blank password. Use
> a strong password."
>
> you can see all supported parameters for command line installation at
> http://msdn2.microsoft.com/en-us/library/ms144259.aspx ..
> never tried omitting the SAPWD=somePwd parameter..
>
> the install wizard, on the contrary, presents you a dialog where you can
> provide the sa password, according you enabled mixed mode
> authentication..... again, never tried leaving it blank, and I hope the
> wizard raises a warning at least if you leave a blank pwd..
> --
> Andrea Montanari (Microsoft MVP - SQL Server)
> http://www.asql.biz http://italy.mvps.org
> DbaMgr2k ver 0.20.0 - DbaMgr ver 0.64.0 and further SQL Tools
> --------- remove DMO to reply
>