DOCUMENT:Q139107 17-DEC-2000 [win95x] TITLE :Err Msg: Uninstall Is Unable to Write to the MBR PRODUCT :Microsoft Windows 95.x Retail Product PROD/VER:95 OPER/SYS: KEYWORDS:win95 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows 95 ------------------------------------------------------------------------------- SYMPTOMS ======== When you try to use the Uninstall option in the Add/Remove Programs tool, you may receive the following error message when your computer restarts: Uninstall is unable to write to the MBR When this occurs, the Uninstall procedure cannot be completed, and you may not be able to start the computer from the hard disk. CAUSE ===== This problem can occur when any of the following conditions exists: - The hard disk's Master Boot Record (MBR) is damaged. - A software or hardware-level virus scanning program is protecting the MBR. - You are using third-party disk partitioning software. - You computer has been infected with a boot-sector virus. RESOLUTION ========== Use the information in the appropriate section below to try to resolve the problem. If you cannot start your computer from the hard disk, you can start it using your Windows 95 Startup disk. MBR Protected by Virus Scanning Software ---------------------------------------- If you suspect that a virus scanning program is preventing Uninstall from writing to the MBR, disable the virus scanning program by editing the Config.sys or Autoexec.bat file to temporarily disable the program. Place the word "Rem" (without the quotation marks) at the beginning of the line or lines used to load the virus scanningprogram. After you make this change, restart the computer. For information about the virus scanning program, consult the program's documentation or manufacturer. MBR Protected by Hardware-Level Virus Scanning Program ------------------------------------------------------ To disable hardware-level virus detection, run your computer's CMOS configuration utility and disable the virus detection. For information about your computer's CMOS configuration utility, please consult the computer's documentation or manufacturer. Third-Party Partitioning Software --------------------------------- If third-party partitioning software is preventing Uninstall from writing to the MBR, refer to the software's documentation for information about restoring the previous MBR or modifying the current MBR. Boot-Sector Virus ----------------- If you suspect that your computer has been infected with a boot-sector virus, use an anti-virus program to detect and remove the virus. For additional information about viruses, please see the following article in the Microsoft Knowledge Base: Q82923 Methods to Detect a Boot-Sector Virus After you resolve the problem that is preventing Uninstall from writing to the MBR, start your computer with your Windows 95 Startup disk, and then run Uninstall by typing the following command at the command prompt " :\uninstal " (without the quotation marks) where is the drive containing the Startup disk and is the full path to the W95undo.dat file. ====================================================================== Keywords : win95 Technology : kbWin95search kbZNotKeyword3 Version : 95 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2000.