[moo2k]

1)

Код:

var
f: TextFile;
fName: String[80];
i: integer;
begin
fName := C:\My Documents\f1.txt';
AssignFile(f, fName);
{$I-}
Rewrite(f);
for i:=0 to Form1.Memo1.Lines.Count do
writeln(f, Form1.Memo1.Lines[i]);
CloseFile(f);

2)

Код:

RenameFile('f1.txt', 'f2.txt');

3)

Код:

SetFileAttributes('C:\My Documents\f1.txt', 38);

4)

Код:

DeleteFile('C:\My Documents\f1.txt');