open old registry files

I had to reinstall windows because of a problem i could not figure out, and it was getting a bit loaded up with crapola i forgot about and generaly being slow (esp booting)
anyhow i did install windows to a different folder and kept the old reg files.
I would like to extract a key from an old registry file and import it to my current registry.

anyone have an idea how to do it? regedit does not let you just open a different reg file.

Actually it does if you are thinking using windows 2000 or newer. Let me clarify, you can load registry hives, getting your keys and what not is up to you, however this isn't done throught regedit.exe rather regedt32.exe... althought this program reminds you of a 16bit program.

Open the program and pring up the window that is eiher HKEY_LOACL_MACHENIE or HEY_USERS and then go to the registry sub menu and the option to load hive will be active. you can navigate to the different sections of the registry on the old installation and read it.

You'll have to specity a name to make a sub key that the registry is loaded in, DON'T FORGET TO UNLOAD IT BEFORE YOU RESTART. Although I haven't had problems I've heard many many many times that it can so don't forget.

The registry is split into different files (I might miss some) here are the ones that I can remeber

%systemroot% (your windows directory)\system32\cofig\
Sam
Security
System
Software

Now if you want your personal registry settings that would be under current user or user (I don't remeber might be booth) Go to

documents and settings\%username%\Ntuser.dat

when i run "regedt32.exe" just the normal registry editor opens? this is a fresh install of windowsXP with sp2 and the "regedt32.exe" file is only 4k, probably just a pointer to regedit.exe

ok i figured out what to do in regedit anyways:
highlight HKLM then "load hive" and load ntuser.dat from documents and settings/oldusername (load hive will not be enabled in the menu unless HKLM is highlighted)
then name the imported hive "test".
there is now hklm/test with all the keys from previous user account
find the key i needed
export it
open it in notepad and replace all
HKEY_LOCAL_MACHINE\test with
HKEY_CURRENT_USER
re import it


woot all my settings are back
and it is much faster to re register software than loading cd, install etc
im just glad i chose a different user name this time or ntuser.dat would have been overwritten
if windows hadnt so totally crapped out i would have backed all that stuff up or. now i will be sure to save reg hive files on regular CD backups.