Title: Get free/total disk space
Use DiskSize and DiskFree functions for this problem.
ComboBox1 contains a list of drives letters.
var
Disk: Integer;
...
procedure TForm1.Button1Click(Sender: TObject);
var
Total, Free: LongInt;
begin
Total:=DiskSize(Disk) div 1024;
Free:=DiskFree(Disk) div 1024;
Gauge1.MaxValue:=Total;
Gauge1.Progress:=Free;
Label1.Caption:='Total size - '+IntToStr(Total);
Label2.Caption:='Free - '+IntToStr(Free);
end;
procedure TForm1.ComboBox1Change(Sender: TObject);
begin
Disk:=ComboBox1.ItemIndex+1;
end;