ERUNT GUI directions

DougCuk · 18 Mar 2015

While it is always potentially useful to have the COMPONENTS registry included in the backup - the issue is whether it is a good idea to restore it. The key point to understand is that the registry is updated in parallel with changes to the filesystem (files and folders) on the hard drive.

Restoring a registry backup that predates large changes to the filesystem (eg Service Packs) is always risky - which is why System Restore is a better option if available. It restores both the registry and reverts the filesystem changes - so you retain a matched pair - the registry and filesystem are in sync with each other.

If you are able to do a System Restore either from the running system or via the Boot CD/DVD Repair option (Vista, Win7, Win8) - then that should be considered first - if that is not available or is considered overkill then a registry restore can be used.

The major filesystem issue for the COMPONENTS registry is the \Windows\WinSxS folder system which stores a large number of critical files (mostly DLL versions) which are hard linked into the rest of Windows. That is files in System32 & elsewhere are really just links into WinSxS.

If the COMPONENTS registry is not in sync with this folder all hell can break loose. Windows Update may stop working, recently installed programs can stop working, program installers and uninstallers can fail - and by the time you realise things are screwed it can be very tricky to fix.

The guidance from the SysNative guru is always use the COMPONENTS registry that is the closest match to the existing WinSxS folder - which may well be to leave the current version in situ - even if you restore all the other registry files or just the SYSTEM registry. Only include the COMPONENTS registry in the restore if you really need to - or it is so recent that it matched WinSxS anyway.

If the registry backup is very recent
- that is no Windows Updates have been installed
- no programs have updated Microsoft runtime packages (eg NET Framework or Visual C++)
then a registry restore with or without COMPONENTS is likely to be trouble free.

The more modern registry backup utilities can backup the COMPONENTS registry regardless of whether it is loaded (Tweaking.com) older utilities only include it while it is loaded in memory (ERUNT). Having an option to choose which parts of the backup are restored is the ideal - I think the Tweaking.com Registry Backup utility may have already added this option. Alternatively you can always remove the COMPONENTS file from the folder you intend to restore - before running the restore - to prevent the utility from restoring that file.

fwcetus · 20 Mar 2015

Thanks, DougCuk, for your detailed summary of the COMPONENTS situation.

You are correct -- RegistryBackup (Tweaking.com) does allow one to pick which hives are to be restored, at least from the GUI -- it seems to me, however, if one is restoring using the dos_restore.cmd batch file, and if it were decided that COMPONENTS should not be restored, then the dos_restore.cmd file must be edited (or the COMPONENTS hive deleted or renamed) before restoring (which, of course, is similar to using the command line restores from ERUNT or RegBak).

I can see, from your treatise, that being cognizant of just when Windows Update was last run can help one decide whether or not to include COMPONENTS in any restore operation. Thanks for your research and your perseverance.