copy the string one character at a time into another variable that is long enough to hold the extra characters. When an '\' is encountered just copy two of them.
But I have to question your reason for doing that. When you type a path from the keyboard into a variable you don't need the couble '\' characters. They are only needed when you use string literals in your program because the compiler has to interpret the characters.
I Developed application in C# with crystal reports and created setup file in third party (Advance) Installer.When i installed my application on client system application is working but ...