DOCUMENT:Q134298 17-DEC-2000 [win95x] TITLE :Older Disk Controllers Incompatible with Protected-Mode Driver PRODUCT :Microsoft Windows 95.x Retail Product PROD/VER: OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows 95 ------------------------------------------------------------------------------- SYMPTOMS ======== After you install Windows 95 on a Compaq DeskPro 16 computer (circa 1988), you may receive the following error message: Your system is not configured for its fastest performance If you click the Details button, you receive the following message: Drive C: using MS-DOS Compatibility mode CAUSE ===== Certain older computers with proprietary disk controllers exhibit this behavior. Windows 95 protected-mode disk drivers are not guaranteed to work with IDE controllers using proprietary firmware to access drives. The proprietary firmware in some older IDE disk controllers is not designed to work correctly with the Windows 95 INT 13 interface. RESOLUTION ========== You must disable protected-mode support for older IDE controllers that exhibit this problem. To do so, disable the IDE/ESDI controller in Device Manager. STATUS ====== This situation is most likely caused by design changes in Windows 95. Microsoft has confirmed that it is not caused by a problem in Windows 95. ====================================================================== Keywords : Technology : kbWin95search kbZNotKeyword3 ============================================================================= 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.