Unlike XP and Vista, Windows 7 does not automatically create System Restore Points at regular 24 hour intervals. Windows 7 will only create a restore point prior to:

*An application installation (provided the application utilizes an installer that is System Restore compliant).

*Windows Update installation.

*Or if no other restore points have been created for [b:23y2p7kn]7 days[/b:23y2p7kn].

Many users will want to utilize more frequent creation of Restore Points and I would recommend users manually create a restore point prior to any new software installation.

Here