You can run Programs|Accessories|System Tools|Backup, then choose ERD, then
if you check the box for "Also backup....", then the reg will also be backed
up to
%windir%\repair\RegBack
leaving the
%windir%\repair\
directory files intact as original installation.

Then archive the files in
%windir%\repair\RegBack
These would, in effect, be registry restore points.

You can replace registry hives from within the recovery console by copying
the files from your archive to;
%windir%\system32\config

To start the Recovery Console, start the computer from the Windows 2000
Setup CD or the Windows 2000 Setup floppy disks. If you do not have Setup
floppy disks and your computer cannot start from the Windows 2000 Setup CD,
use another Windows 2000-based computer to create the Setup floppy disks.
Press ENTER at the "Setup Notification" screen. Press R to repair a Windows
2000 installation, and then press C to use the Recovery Console. The
Recovery Console then prompts you for the administrator password.  If you do
not have the correct password, Recovery Console does not allow access to the
computer. If an incorrect password is entered three times, the Recovery
Console quits and restarts the computer. Note If the registry is corrupted
or missing or no valid installations are found, the Recovery Console starts
in the root of the startup volume without requiring a password. You cannot
access any folders, but you can carry out commands such as chkdsk, fixboot,
and fixmbr for limited disk repairs. Once the password has been validated,
you have full access to the Recovery Console, but limited access to the hard
disk. You can only access the following folders on your computer: drive
root, %systemroot% or %windir%

In most cases replacing the software hive will do it.