Update:I have been able to keep restore points for over a month now!
I was correct in my assumption that Norton Internet Security was
deleting my restore points. I read in another forum/thread that you need
to turn off the protection for Norton products. I did so by going to the
Norton Internet Security Online Options window and I cleared the
checkbox where it says,"Turn on protection for Norton products
[recommended]",and ever since then,for a whole month,I have been able to
keep all of my restore points except for the first few since system
restore is setup to use only about 40gbs of my harddrive space.

But,it is probably not a good thing though,because since I
turned off the protection for Norton products,the Norton software is
vulnerable to hackers and unauthorized changes to Norton files and
settings or so it says. I'll try to figure out a way around this. I
guess Norton views system restore points as threats because restoring to
an earlier restore point might cause your computer to become reinfected
which will,in turn,cause unauthorized changes to the files and
settings,I guess. I'll see if I can alter how it views system restore
files-I'll go to the Norton site and see what it says about it.
But,thanks a lot everybody for responding to my posts! I really
appreciate the help!
I still have other problems with my computer that I will address in
other threads if I can't figure them out myself:

For the past 3 months,occasionally,my Windows Explorer and
Internet Explorer Windows have become black,distorted and/or
nonresponsive and I end up just having to restart my computer,and if I
let it go long enough,it spreads to the taskbar items and startmenu
also. I'm going to try downloading Internet Explorer 8 and see if that
fixes the problem. Plus,I have lost Windows Update History twice since I
done the recovery with automatic data backup in October,but I can still
find all of the windows updates under installed updates. Also,my laptop
occassionally fails to read a disc it has burned. My laptop's warranty
ends on May 10th and in addition to the problems I have mentioned in
this thread,I have already had 2 batteries and an adaptor replaced
because battery indicator in taskbar stated that it was "plugged in,not
charging" and this would result in my computer shutting down. And,to top
it off,the fan had to be replaced in February and this all happened in
the first 9 months of having my laptop. I'm hoping none of these
problems are due to motherboard or hard drive issues. My hard drive does
make a sizzling type a noise which may be normal-I don't know?
But,anyway,hopefully,I have helped someone with Norton Internet
Security who is losing restore points. All you do is,just turn off
protection for Norton products and that should stop it from deleting
restore points.
Thanks,
Tonya
--
TGL