How do I set Audacity to remember the position of the interface tools? Because I set them how I want, but they do always reset on the next program start…
pls help… 
If you mean the Toolbars ( http://manual.audacityteam.org/o/man/toolbars_overview.html ) they should stop put if you float them out of their docked position. This assumes you are using the current Audacity 2.0.3 from http://audacityteam.org/download/ .
Gale
Yeah, I have Audacity 2.0.3. I send you two pics of it so you can understand my problem… 
This is how I want the toolbar…
And this is how it resets on every new program start…
The way you show it resetting is how it would be by default on a wide monitor with a fresh installation on a machine that never had Audacity before.
I don’t have a wide enough monitor to set up your layout in the first image, but I suggest you reset preferences as described here then try to apply your customisations.
Gale
I think there is a minor bug here.
The code looks as if it is intended to save the size of the Device Toolbar down to a minimum size of 200 pixels, but it actually restores to the maximum of the saved size and the default size. The default size is 620 pixels, so in effect that is the minimum size that will be restored after restarting Audacity. The same issue exists with the meter toolbar, but the default size and minimum size are quite similar so that is hardly noticeable.
Thanks, yes the issue is documented for Meter Toolbar ( http://bugzilla.audacityteam.org/show_bug.cgi?id=573 ) but not for Device Toolbar. Device Toolbar does respect resizing downwards if undocked.
However since BlackWhiteX isn’t trying to get a reduced width Device Toolbar I’m not sure what the problem is here.
Gale
It looks to me like the Device toolbar in the arrangement that he wants is just under the default size, but that is just enough for the toolbar to resize and no longer fit where he wants it. If you look closely, the recording input and playback output boxes show a couple more characters in the second image.
Yes you are probably correct, Steve.
If I was the user I would float the Device Toolbar to left of the Minimize button in the Title Bar then Device Toolbar would stay put.
Gale
Yeah, in fact both device toolbar and meter toolbar return to their original size on each program restart… But I think the problem is the monitor size, which is slightly too small to contain the standard size of every toolbar… it’s strange 'cause it worked properly on the versions before 2.0.3… i’ve been using Audacity since almost 5 years and I always had this config of the toolbars on the same pc…
however, I will try to find another solution…
thanks to all for helping me!!! 
this forum is one of many reasons why I will always use Audacity!!!
P.S. I’m sorry for my bad english, but , you surely noticed, I’m not a native speaker… I’m doing my best to communicate in proper english 
The default width of Device Toolbar and Meter Toolbar was increased slightly for 2.0.2. This increase is probably enough to cause the failure to fit the toolbars the way you want them. The bug of resetting to default width if docked and reduced below default width exists in all the 2.0.x versions.
By the way your English is very understandable.
Gale