I have a lot of computers in my network and i need to get info about the software and hardware installed on all of them Is there any software to make such network inventory and audit?
['https://superuser.com/questions/73724', 'https://superuser.com', 'https://superuser.com/users/-1/']
If you want to gather inventory/audit information **programmatically**, then use [WMI](http://msdn.microsoft.com/en-us/library/aa394582(VS.85).aspx).

WMI has a good .NET interface that is readibly available from within Visual Studio 2008 as a collection of library classes. PowerShell also exposes this interface for scripting.
You can try Spiceworks, it is free software with promo, also I’ve heard that the network inventory software by Clearapps is wide spread among sysadmins. It’s not free, but has more wide functionality. Or you can just google search and find everything here: 

<http://www.google.com/search?hl=en&source=hp&q=pc+inventory+software&aq=f&oq=&aqi=g4g-m2>