Please help. I can't open task manager by clicking Ctrl+Alt+Del or by right clicking on the task bar as wellas if I write it on run. But when I write it on cammand line, it says Access denied on the command line window and there is a pop-up window that says It is not a valid Win32 Application. I am using Windows 2003 SP1. I haven't been able to install updates either. If this might help I had found trojan horse on my PC, but I have cleaned it now. But I'm not sure the trojan horse was there before I was unable to open the task manager. I have tried scanning in safe mode and trying to open it, but it doesn't work. In the system32 window, tskmgr.exe is 0KB and so are many other exe files like tcmsetup.exe, systray.exe and sysocmgr.exe Hayat _________________________ Computers are not intelligent, they just think they are.