Sandy, please see this page:
http://www.computerhope.com/issues/ch000239.htm
It appears you are confusing Windows settings with your computer's actual
settings.
It sounds like your CMOS battery on your motherboard does need changing.
But before you do that, you need to enter the BIOS and write down all the
settings. It's possible they are still all at the default value, but in
the event any were changed along the way, you need to know what they are!
The reason: removing the battery turns off your CMOS and your settings
will revert to the default ones.
Accessing the BIOS depends on what PC you have. It involves pressing a key
right after you turn on your PC (actually, right after you see the first
splash screen. If a Windows splash screen comes up, it's too late and you
need to try again.). See this page for which key you need to press for
your PC:
http://www.michaelstevenstech.com/bios_manufacturer.htm
FWIW, Windows Systen Restore sets regular system restore points (usually
every 24 hours as a rule, or whenever you install programs or updates).
It's very useful, and people do use it to return their Windows system to
earlier settings (best results would be for *recent* changes).
Unfortunately, some third-party programs (Norton programs, for instance)
interfere with Windows System Restore. If you want to see how far back
your restore points go, do the following:
Start | All Programs| Accessories | System Tools | System Restore
(there are other ways to access System Restore, too)
By default, "Restore my computer to an earlier time" is selected. If you
click on Next, you will see a calendar with a choice of dates. Don't
actually go through with the System Restore! I'm just letting you know
this option should be available. You can also manually create a restore
point if you wish. For more info:
http://bertk.mvps.org/
http://bertk.mvps.org/html/srfail.html
http://www.microsoft.com/windowsxp/using/helpandsupport/getstarted/ballew_03may19.mspx
http://www.bleepingcomputer.com/tutorials/tutorial56.html
I know, more info than you asked about! It still wouldn't be a bad idea to
bookmark one or two of these pages for future reference. It might wind up
saving you lots of aggravation.