How do I retain my System Restore points?

I created a system restore point the other day, and today I go to check and it's gone. I have about six restore points all from today.
What happened to the one I created? I thought that was the purpose of making one, so I can go back to it if needed.

Just made another restore point but I don't know what good it will do.

System restore points (also called shadows) are kept in the shadowstorage. For that the system reserves up to 15% of your OS partition (usually C partition). Once this is full, it will reuse the space. Each shadow (restore point) is about 1GB in size and they are written one per day and every time something is being installed (program or update). If you want more restore points, you have to increase the shadowstorage - but that may not be practical. To inspect the shadowstorage or change anything you use the VSSADMIN command in elevated command prompt ( Vssadmin ).
But if you want to keep particular points in time of the system, you have to do imaging. Long time ago I started a thread on that. It may give you an idea. Note: Ghosting and Imaging are the same thing. ( Ghosting approaches - summary because of popular demand « How-To Geek Forums )

Thank you for the info whs.
I'm going to download the free trial of Acronis True Image Home 2010 and see how it works out.($50 to buy)

Here are some free imaging programs that you might consider. The free Macrium is being praised by people that have used it. 7 Freeware Acronis True Image & Norton Ghost Alternatives Also, if you have an external disk, check whether it did not come with a free imaging program - e.g. Maxtor does (it works also on Seagate disks - same company).