c# - Debug stepping not working after enabling then disabling "Enable .NET Framework source stepping" in VS2010 -

i'm new programming , ides in general. messing around in [tools] [options] [debugging] in vs2010 , program not stepping through code previously. checked "enable .net framework source stepping" option , attempted dowload symbols. unchecked option , program not step form1 code after form launches , button clicked. help.

in same settings, "enable code (managed only)" checked? when check "enable .net framework source stepping", vs2010 uncheck other option (they mutually exclusive).