By system restore, I assume you mean an OS reinstall. In that case, the below applies.
If the .NET Frameworks in question are embedded in the OS, then yes.
If the .NET Frameworks in question were installed by the user, then no.
If you have XP, which has no embedded frameworks, you'll have to reinstall any .NET Framework versions you had previously.
If you have Vista, .NET 2.0/3.0 is embedded. Any higher version will have to be reinstalled.
If you have Windows 7, .NET 2.0/3.0/3.5 through 3.5 SP1 is embedded. Any higher version will have to be reinstalled.
If by system restore, you mean apply some computer maker's proprietary image, there is no way to predict what (if any) .NET Framework versions beyond the above might be restored.
In all cases:
You can check what .NET Framework versions are installed on your system with this tool:
http://blogs.msdn.com/b/astebner/archive/2008/10/13/8999004.aspx