Microsoft Visual C# 2005 Express Edition Build Error

When I write code in Visual Studio and trying to debug it then I receive given error after it I remove my code and then I take code from internet and try to debug that code but same error appear again please tell me why this error appear and tell me its solution.

Microsoft Visual C# 2005 Express Edition
There were build errors. Would you like to continue and run the last successful
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Thanks for providing help
