Without a CD to run a repair install, you're in trouble. The folder you quoted holds a major section of the system's Registry - the huge "filing cabinet" in which all the details of your system are stored and every programme consults it before starting and during operation.
Try tapping the Function 8 key when you power up the machine and if you see the Advanced Boot menu, select Safe Mode with Command Prompt. If you can get that far, leave the page showing and post back for what to do next.