As system restore can be really useful for you in case your windows configuration gets mess up it can also compromise the performance and the life of your hard drive.It will take you about a minute to adjust and not doing it will cost you hours in the long run, so please take a minute now and do it!Here are the instructions:

1. - Right click on My Computer icon and select properties this will bring you to the System Properties Window.

2. - Click on the System Restore tab.

3. - Slide the Disk Space Usage to the minimum as you can see in this case we brought the slider to the minimum because is a big hard drive 500 GB, but in case your hard drive is 15 to 40 GB don't bring the slider under 1 GB as you need this space to have a good amount of system restore points in case that you need to restore your computer at certain point.

4. - After you selected the amount of disk space that you want to use click Apply then Ok and you are done!

As you can see on this window you can also turn off System Restore by checking the little box at the top of the window, if you never use System Restore you can go ahead and disable this service. But I suggest keeping it on as it can save your windows configuration at anytime just make sure you are not using 30 GB of your hard drive for these files as is useless.