Frequently Asked Questions
Q: What tools does Startup Repair use to diagnose and fix difficulties?
A: The recovery tools used by Startup Repair are the following:
- System Restore: System Restore is the preferred recovery method in many cases, as it has a better chance to put the computer into a stable state if it runs successfully.
- Chkdsk: If file system metadata is corrupted, Startup Repair launches ChkDsk for repair. This is done as a last resort, as ChkDsk can potentially change the system state.
- Boot Critical Disk Meta-data Repair (BCDMD): BCDMD repairs missing/corrupted MBR code, partition table, or boot sector (at least one must be intact), or missing/corrupted boot manager. These operations are non-reversible; therefore, prior to any repair, BCDMD ensures that the computer is indeed in an invalid state.
- Memory Tester: If diagnostics determines that the most likely root cause is bad memory, Startup Repair schedules the memory tester. This tool must be run outside of the WinPE context because it is a boot application. Therefore, Startup Repair schedules the tool to run with the boot manager. If the tool runs successfully and Windows Vista recognizes which pages to avoid, the operating system starts up and Startup Repair's post-boot experience takes over. If the tool fails to indicate which pages to avoid, the failover mechanism takes the computer back into Startup Repair for further diagnostics.
- XCOPY: In the event of an issue that can be fixed by restoring a replacement copy of a file or files, such as registry corruption, Startup Repair uses XCOPY to perform this copy operation.
- From Registry Backup: In the event that a registry hive is corrupted, Startup Repair has the option to replace the entire registry with a backup taken every 6 hours. These backups are located in the \Windows\system32\config\regback folder. The entire registry needs to be replaced because changing one hive leaves the computer in an inconsistent state. The diagnostic unit of Startup Repair utilizes the log written by the loader to determine which registry hive is corrupted or cannot be loaded. Crash dump, if available, is also used to determine which registry hive is corrupt.
- From driver store: When a driver is damaged, Startup Repair can copy a replacement from the driver store.
- From WinPE system components: If system files have been damaged, WinPE system components can be used to make the replacement.
Note: Some of the information in this document was provided by Microsoft.
