System Restore is a tool included with Windows to change all the system settings back to a previous time. System restore keeps what the registry settings were for your machine and other settings. The registry keeps track of all setting to run Windows and programs. System Restore does not back up data, just the settings. When you install some Windows updates, Windows will automatically do a System Restore point. If you are installing a program you are not sure how will ruin in Windows version you have, do a system Restore point first. If you install programs after a system Restore point is made and you go back to that point you will lose those programs installed after it.
I was recently fixing a Windows computer that would go to a black screen with just an arrow after restarting after some updates. System restore made it easy to set the system back to where it was before the update and then to go on working.
If Windows will not start correctly it will give you an option to recover the system and then give you an option to go to system restore. At System Restore you will be given a list of system Restore points, mostly by date and you can choose one and the system will reset settings to that point and try to start. If needed you can choose then to go to another restore point.
To create a system restore point you will right click on Computer in Start menu Windows 7 or prior and choose Properties or go to system and security, then system in control panel by your option menu on right of screen in Windows 8, (you can also use the Windows 8 method on previous versions of Windows of going to Control Panel). Then choose Advanced System Settings, then System Protection tab, then the create button at the bottom. It will automatically put the date on the system restore point but will prompt you to add a more descriptive name for instance “install photoedit” if installing a photo editing program. The restore point is then created and saved.