If you haven't rebooted after enabling system restore then it isn't available despite the monitoring status.
You may also have to create a clean restore point, assuming your system is clean.
Create Clean Restore Point - Clear old Restore Points.
Now you are clear of infection create a clean System Restore point:
1. Click Start, All Programs, Accessories, System tools, System Restore.
2. In the pop-up that appears fill in the radio button to Create a Restore Point
3. Click NEXT
4. Enter a useful name that you will remember if you need to find this again (Clean Restore Point)
5. Click CREATE
You now have a clean restore point, you should clear the old ones:
1. Click Start, All Programs, Accessories, System tools, Disk Clean Up
2. Click OK on the C: drive
3. Click the More Options tab
4. In the System Restore section click the Clean Up button