"To delete restore points either:
1) Use Disk Cleanup. It will delete all but the most recent restore point or
2) Disable System Restore. As soon as you do, all restore points will be immediately deleted or
3) Reduce the space allotted to System Restore." Quoted From Allen
Thanks for your reply Allen! All good suggestions, but these are different. These remain after you delete old back up images on your external hard drive. They are different from restore points. They remain even after doing all the things you suggested. There may be other ways to delete them, but this is the only way I have found to get rid of them. If you have more than one External hard drive, you will need to do the same steps for each drive. Your reply will work good for deleting old restore points and can be used along with this to clean up your HD.
Thank you!
PS These are System Image Restore Points. The others are just restore points.