System Restore is a component that come with Microsoft windows versions.So when you are dealing with lot of programes there can be a chance to occur errors.sometimes installation or unstallation of a program will affect to your Windows to behave in unpredictable manner.So if you don't now what to do next.you will get more troubles.may be your system get crash and you will have to reinstall your Windows OS again.It will causes to loss of your data.so how you overcome this problem.
System restore comes there to help you.It will help you to restore your system files to earlier date of time that everything worked perfectly.Usually when you install a big program that make lot of changes in registry ,Windows will automatically create system restore points for you.but if you want you can create them manually also.But remember this technique is not backing up your personal files.this will only care about Windows system files that needed to run OS perfectly..
Opening System Restore Window.Start-->All Programes-->Accessories-->System Tools-->System Restore.

In here you can decide what to do next.You can either Restore your computer to earlier date or you can create a restore point there.
Restore your System to earlier dateThis calender will show you what restore points are available for you.You can select a date from the calender.When you select a date ,right side of your box will show more descriptive things that what are the changes that made on that day.So you can select the exact change from this box also.

After selecting all the things Click NEXT.
There it will show you a summery of that particular system point.

Then if you press NEXT it will start to restore your system to that selected system restore point.
Create a Restore PointSO if you are currently happy with the current situation of your PC you can tell to OS that remember this situation.if somethings go wrong take me to this situation.

So in here you can give a name for your System restore point.
eg: Best Condition Ever.
So Press CREATE.