Article ID: 186909 - View products that this article applies to.
This article was previously published under Q186909
When Windows starts, the Registry Checker tool may display the following message:
Windows registry is damaged. Windows will restart and try to fix the problem.
When you click OK, you may receive the same message when Windows restarts.
Note that running the real-mode version of Registry Checker (Scanreg.exe) at a command prompt does not detect registry damage, and Windows Millennium Edition (Me) does support real mode Scanreg.exe.
This problem can occur if there is defective memory in your computer. A defective memory chip may damage the registry in memory. The Windows-based (or protected-mode) version of Registry Checker (Scanregw.exe) scans the registry in memory for damage.
When this issue occurs, Scanregw.exe detects that the registry is damaged in memory and marks the registry as damaged so that the real-mode Scanreg.exe is run the next time the computer starts. Scanreg.exe may not detect any damage if the defective memory is not used in real mode, and may allow Windows to start normally.
There are two methods you can use to identify whether defective memory chips are causing the problem:
Method 1Remove or replace memory chips in the computer to see if the problem is resolved.
Method 2Try limiting the amount of memory that Windows uses. If limiting the amount of memory that Windows uses resolves the issue, the problem is a defective memory chip. To limit the amount of memory Windows uses, follow these steps:
For more information about troubleshooting memory, please see the following articles in the Microsoft Knowledge Base:
TITLE : Parity Error Messages May Indicate Bad Memory
TITLE : How to Use a RAM Drive to Troubleshoot Memory
You can disable Registry Checker so that it does not run automatically at startup. To disable Registry Checker, use the following steps.
WARNING: Microsoft does not recommend disabling Registry Checker. This tool automatically guards against problems that may render your computer unusable. The symptom described in this article may be indicative of a larger problem that should be identified and addressed.
The real-mode tool (Scanreg.exe) is run at startup when the registry flag is set for either damage or optimization. If the damage flag is set, Scanreg.exe scans the registry for damage and then automatically restores the most recently saved backup set. The backup is extracted to a temporary file and scanned for damage before it replaces the current files. If the backup is damaged, the next most recent backup is restored. If no backups remain, Scanreg.exe attempts to fix the damage by rebuilding the registry without errors or empty data structures. If the optimization flag is set, the registry is compressed by removing all but a 4 KB placeholder for each empty data structure. The registry is not rebuilt when it is optimized; 4 KB remains to serve as a placeholder within the current registry.
For additional information about the Registry Checker tool, please see the following articles in the Microsoft Knowledge Base:
TITLE : Description of the Windows Registry Checker Tool (Scanreg.exe)
TITLE : How to Customize Registry Checker Tool Settings
TITLE : Command-Line Switches for the Registry Checker Tool