Scenario 1: after PAEPATCH 32Bit Windows to use more than 3.5 GB or RAM, sometimes Startup becomes corrupted. Thus, one must follow procedure to fix Window’s Master Boor Record (MBR):
1. Fix BCD <——- Confirmed as Effective Procedure!
(http://answers.microsoft.com/en-us/windows/forum/windows_7-system/automated-startup-repair-fails-cannot-find-os/81789756-858e-4adc-a25b-2c0d0c234e0d)
a. start with Windows CD/USB and choose recovery options
b. CMD> bootrec.exe /FixMbr
c. Rebuild BCD:
-
-
bcdedit /export C:\BCD_Backup
-
c:
-
cd boot
-
attrib bcd -s -h -r
-
ren c:\boot\bcd bcd.old
-
bootrec /RebuildBcd
-
Scenario 2: after a registry edit, Windows could not start. One must try the following procedure:
2. Restore registry (http://www.registryfix.net/restore-registry) using commands
Run these commands in recovery console
md tmp
copy c:\windows\system32\config\system c:\windows\tmp\system.bak
copy c:\windows\system32\config\software c:\windows\tmp\software.bak
copy c:\windows\system32\config\sam c:\windows\tmp\sam.bak
copy c:\windows\system32\config\security c:\windows\tmp\security.bak
copy c:\windows\system32\config\default c:\windows\tmp\default.bak
delete c:\windows\system32\config\system
delete c:\windows\system32\config\software
delete c:\windows\system32\config\sam
delete c:\windows\system32\config\security
delete c:\windows\system32\config\default
copy c:\windows\repair\system c:\windows\system32\config\system
copy c:\windows\repair\software c:\windows\system32\config\software
copy c:\windows\repair\sam c:\windows\system32\config\sam
copy c:\windows\repair\security c:\windows\system32\config\security
copy c:\windows\repair\default c:\windows\system32\config\default
Reboot | Press F8 | Enter Safe Mode
Tools | Folder Options | View tab | Show Hidden Files and Folders
Find Restore Point Folder, which always start with “RP”
Open “Snapshot” folder and copy the following into C:\Windows\Tmp folder and rename them:
_REGISTRY_USER_.DEFAULT (rename to DEFAULT)
_REGISTRY_MACHINE_SECURTY (rename to SECURITY)
_REGISTRY_MACHINE_SOFTWARE (rename to SOFTWARE)
_REGISTRY_MACHINE_SYSTEM (rename to SYSTEM)
_REGISTRY_MACHINE_SAM (rename to SAM)
Restart and go back to Recovery Console
del c:\windows\system32\config\sam
del c:\windows\system32\config\security
del c:\windows\system32\config\software
del c:\windows\system32\config\default
del c:\windows\system32\config\system
copy c:\windows\tmp\software c:\windows\system32\config\software
copy c:\windows\tmp\system c:\windows\system32\config\system
copy c:\windows\tmp\sam c:\windows\system32\config\sam
copy c:\windows\tmp\security c:\windows\system32\config\security
copy c:\windows\tmp\default c:\windows\system32\config\default
Restart and perform System Restore