to delete file with visual studio c

Sorry, my last link is incorrect, please visit:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/base/deletefile.asp

Or you can just use system("del C:\\folder\\file.txt"); (Or on *NIX, "rm /home/folder/file.txt")
That will work regardless of your build environment.

There is also the run time library function remove that goes back to pre Windows days

int remove ( const char * path)
int _wremove ( const wchar_t * path)

Function returns 0 if successful and -1 if not. If -1 then errno is set to EACSS (file read only or is open) ENOENT to indicate path not found.

This is for information only - if possible I would go with jaime_olivares recommendation.

Oh just a comment on system - it will work but your return values are not as significant as for DeleteFile and remove - with the latter you can get more information about why a delete failed.

Again for info purposes and not an attempt to lessen ch0c's suggestion which is still valid.