Replacing hive files

I have windows 2000 pro.
I had a bad run of viruses and feel good about eradicating them.
But I must have damaged the registry along the way because I can't install printers and the USB scanner is not recognized correctly.
My next idea is to reload an older version of the registry (because it likely has the keys that I erroneously deleted) then import all the keys from my current registry file. Kind of a superposition of the old and the new.
I don't fully understand how regedt32 works for restore hive and load hive. So I have 3 options:
(a) with my current system running, use regedt32 and "restore hive" from the date 9-17-01 for each of the default, sam, security, & system files.
(b) do teh same as (a) but use "load hive"
(c) boot dos from a floppy and replace the 4 hive files in the winnt\system32\config directory with the files from date 9-17-01. Boot and import the registry keys from 1-05-06 to add to the registry.

Will any of these options work or will I just corrupt the sytem? Will I be able to log on when I reboot? I have completed a system backup, but will I be able to repair my system from dos and system restore? I don't have a windows CD (it's lost) so can't run recovery console.
Thanks for any insight you can share, Mark

 

I dont know but you could always backup the current registry and if everything does not work again you can put back the backed up one.