Microsoft Windows Troubleshooting Guide
- Introduction
- Malware Removal
- Fixing Networking Problems
- Repairing a System that Won't Boot
- Optimizing Windows
Last Ditch Attempts to Get the System to Boot
If repairing the Boot Loader or Scanning the Partition for errors doesn't fix your problem, then I would first do a Logged Boot and view the bootlog to see if you can see what the problem is first and try to fix it. If you can't seem to figure out the problem, there are a few more things you can try.
Restoring a Previous Registry
While half of the time a corrupt partition filesystem is to blame for not being able to boot, the other half of the time a registry error can cause your system not to boot. Unfortunately, to fix a registry error, it does take quite a few commands (and a good registry backup) to get your computer to be able to boot again.
Note: Before you try to restore a previous registry, I highly recommend that you attempt to boot from a Microsoft DaRT CD, as when the DaRT environment initializes it will check to see if the registry is corrupt and if it is, it will either repair it or restore a recent backup of it.
Also, their is a utility called Registry Restore Wizard on various Boot CD that will restore a previous registry from a System Restore Point, this is kind of an automated way to do what I will explain how to do below. You can get a copy of the Registry Restore Wizard here
To run the following commands, you must either use a Boot CD that will give you read/write access to the Windows partition, or put your drive into a working system and run these commands on your Windows Partition from that system. Note that the Windows Recovery Console will not work to run these commands because it will not allow read access to the "System Volume Information" folder.
First, backup the existing Registry - You can do this with the following commands using a GNU/Linux Boot CD:
mkdir /windrive ntfs-3g /dev/sda1 /windrive (this could be /dev/hda1 if using ide drives) mkdir /windrive/regbackup cp /windrive/WINDOWS/system32/config/system /windrive/regbackup cp /windrive/WINDOWS/system32/config/software /windrive/regbackup cp /windrive/WINDOWS/system32/config/sam /windrive/regbackup cp /windrive/WINDOWS/system32/config/security /windrive/regbackup cp /windrive/WINDOWS/system32/config/default /windrive/regbackup cd umount /windrive
Now, copy a System Restore Point Registry to the config directory - To do this, you have to figure out which System Restore Point is somewhat recent, you can do this using a Linux CD by issuing the "ls -l" command to find out the dates of the folders. The System Restore Points are located in the "System Volume Information" directory. Here is an example (remember that GNU/Linux has Tab Completion):
mkdir /windrive
ntfs-3g /dev/sda1 /windrive (this could be /dev/hda1 if using ide drives)
cd /windrive/System\ Volume\ Information
ls -l
cd _restore{2E926FD9-.......}
cd RP1/snapshot
cp _REGISTRY_MACHINE_SYSTEM /windrive/WINDOWS/system32/config/system
cp _REGISTRY_MACHINE_SOFTWARE /windrive/WINDOWS/system32/config/software
cp _REGISTRY_MACHINE_SAM /windrive/WINDOWS/system32/config/sam
cp _REGISTRY_MACHINE_SECURITY /windrive/WINDOWS/system32/config/security
cp _REGISTRY_MACHINE_.DEFAULT /windrive/WINDOWS/system32/config/default
cd /
umount /windrive
Now, when you restart the computer, you will be using the restored Registry. If it doesn't work, simply copy the registry backup that you created back and try again with another System Restore Registry (or go on to the next step).
Restoring a Previous System Restore Point
If restoring a previous Registry does not work, you can try to restore an entire System Restore Point, which will restore the Registry and quite a few System and various other files. To do this on a System that will not boot, you must obtain a Microsoft DaRT/ERD Boot CD (see previous page) and boot from it. The DaRT system includes a utility to restore the system using a previous Restore Point.
Using Microsoft's DaRT/ERD to Restore a Previous Restore Point
Warning: Ensure you have a good backup of at least your User Profile (located in "C:\Documents and Settings" on Windows 2000/XP/2003 and "C:\Users" on Vista/2008/7) as restoring to a previous System State is known to overwrite User Preferences and Documents in some instances. Also note that if you use DaRT/ERD to restore the system, it will backup the current configuration to the root of the System Drive at "C:\ERDUndoCache" in case it overwrites any important information. You can also use DaRT to undo the System Restore if it does not work (again ensure you at least backup the User Profiles that you absolutely need).
Running a Recovery Installation
If your system still does not boot after you attempt to use a System Restore Point, you can try booting off of the Windows Installation CD and running a "Repair" install. If it works, you system will boot up with most of your settings in tact. Note that if you do run a Repair install, you should immediately (re-)apply the latest service pack and install all the latest updates from Windowsupdate.
If all else fails, backup all of your files and re-install Windows, formatting your Hard Drive in the process.
