lable text no change in windows xp

Question

Hi

I program in Windows 7 and Visual Studio 2010 is written. The program runs correctly on Windows 7, but Windows XP can be difficult for some parts.
Example: This part of the code will not run on Windows XP.  While one runs correctly on Windows 7. 

lable_range.Text = number.ToString();

 

number is  intiger.