I wrote a program in c# ,it works in my computer but in some other computers it gives exception not exactly the same but like your exception ,I found out in my case the problem is in regional settings where you choose main language for your computer ,for example if you choose English(united states) it means you choose 120,234,123.234 to be your standard for numbers ,if in any case you use int32.pars("120,234,123.234") your computer will get it like a correct number and gives you a int32 correct format but if you change your language to one of other "international" languages (in my case russian )your standard will change and your computer will know 120 234 123,234 as it's standard ! it means for example if you read from file with international standard and your computer understands US standard you will get this kind of exception :
System.FormatException: Input string was not in a correct format.
at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
and...
it doesnt have anything to do with installing SP3 and installing .net framework
I tried it !
about config file ,I dont know if I'm right but it seems if you want to change sth in your exe file and you dont want to compile it in for example visual studio you can add to your project config file and write in it (for example <add key="button1.text" value="10"/>) and you will be able to copy exe file and config file where you want and just change this values or other parameters without compiling your program again and have changes done in your program ,in this case the default text for button1 .
for more info search for configuring an application
A configuration file is simply an XML file with appropriate tags and appropriate name<name>.<extension>.config (e.g. application.exe.config )
High-level .config file schema elements are:
<startup>,<runtime>,<system.runtime.remoting>,<system.net>,<mscorlib>,<conf igSections>,<system.diagnostics>
I tried to use this :
<configuration>
<system.windows.forms jitDebugging="true" />
</configuration>
or <system.windows.forms jitDebugging="false" />
not helpful if you have "string problem" !
I would recommend you to check code where you try to read string and convert it to float,double,int or... you could use messagebox.show() to see if string you want to convert has correct form.
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Windows Vista 
yea 
