You can use Windows Installation DVD to try system restore again. Also i can guide you to replace corrupted registry hives with backup registry hives.
Do you have access to another working computer where you can create Windows Installation DVD?
Windows Installation DVD also can be use to repair install Windows while keeping your installed programs, personal files and most of your settings.
Can you again execute Sfc /Scannow
command, maybe there are corrupted system files need repairing.
Also boot your computer by tapping F8 key and from Advanced Boot Options menu and if there is a option to Repair your computer
selected and press Enter key.
If you can boot your computer into Windows Recovery Environment (WinRE)
using Advanced Boot Options menu then try System Restore tool and Startup Repair tool.