I lost some of my applications code coz of PC format, one of these applications is a C# Console Application, I managed to get the exe output of this application but I was not able to retrieve the code files so I used (.NET Reflector) to do this:
1- Download the .NET Reflector.
2- Download the Reflector.FileDisassembler.
3- Extract the .Net Reflector
4- Extract the Reflecter.FileDisaembler
5- Copy the Reflector.FileDisassembler.dll to the .Net Relector Folder
6- Start Relector.EXE
7- From the View menu select Add-Ins
8- In the Add-Ins Screen select Add and select Reflector.FileDisassembler.dll then close the Add-Ins screen
9- From File menu select Open and select the exe file you want to retrieve its code
10- The reflector will load the file Assembly in the Assemblies section
11- Select the required file and from the Tools menu select File Disassembler
12- Click Generate and you will get your code
Finally I would like to thank Siderite for his help