Explaining what ne555 said:
You should make sure that your string will be seen as one argument by start. Usual way to do this is put string in quotes (which you should escape as they are special characters: \"): system("start \"C:\\Users\\Nero\\Desktop\\cod4launchers\\Call of Duty(R)4 - Snip only\"" );
i open program files whit this: progra~1...something like that...
Sounds like you are using a compiler [and possible integrated development environment (IDE)] that is so old that it only supports what are now called short file names (8.3 format). Get a newer compiler that supports long file names. What is your compiler name and version number? What is your operating system and version number?
Starting with Windows 95, Windows consumer line has supported long file names. I do not know where in the Windows NT, Windows 2000, etc. chain that long file names were added, but they were definitely supported in Windows 2000.