It's a good idea to do a manual scan before installing a new application, as this is one of the most frequent causes of system failure. SecondChance doesn't give you a reminder to do this, though. However, this feature will make it into future iterations. The results of scans are stored as Checkpoints and, as well as restoring everything to the state it was when the scan was made, you can pick out individual folders to restore. This is useful if you accidentally hit Save instead of Save As when editing a document and need to get back to the original.
Checkpoints occupy hard disk space.
When space is limited, old checkpoints are deleted. You can alter the amount of space allocated to storing Checkpoints from the default of 10 per cent of your hard disk. You can view and change this at any time, but the software won't issue a warning if it's getting close to the limit. It goes some way to redeeming itself by letting you ask it to issue a warning before deleting old scans. You can't set up user profiles like you can with ConfigSafe, but you can choose to include or exclude particular directories in a scan.