Disable System Restore from the Control Panel > System > Advanced > System Protection > remove the check mark in Enable System Restore. If your HDD is partitioned, Select the partition > Configure > mark Turn Off System Protection or drag the Max Usage slider to the left so it reads 0%. This will delete the System Recovery directory contents and delete all System Restore points for the selected drive. Once the directory is empty, restart the computer and enable System Restore/Recovery and drag the Max Usage slider to assign the desired disk space for System Restore.