DOCUMENT:Q165503  28-JUL-2001  [win95x]
TITLE   :Description of the File System Troubleshooting Options
PRODUCT :Microsoft Windows 95.x Retail Product
PROD/VER:95
OPER/SYS:
KEYWORDS:kbenv kbtool diskmem win95 kbDiskMemory

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The information in this article applies to:

 - Microsoft Windows 95 
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SUMMARY
=======

The System tool in Control Panel contains a set of options for changing file
system performance settings. You can use these options when you experience
hardware or software compatibility problems.

NOTE: Enabling any of the file system troubleshooting options may seriously
degrade system performance.

MORE INFORMATION
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To display the file system troubleshooting options, follow these steps:

1. In Control Panel, double-click System.

2. Click the Performance tab.

3. Click File System.

4. Click the Troubleshooting tab.

The following table describes the settings on the Troubleshooting tab:

   File system option    Description
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   Disable New File      This option alters the internal rules for file
   Sharing And           sharing and locking on hard disks, governing
   Locking Semantics     whether certain processes can have access to
                         open files in certain share modes that guarantee
                         a file will not be modified. This option should
                         be checked only in the rare case that an
                         MS-DOS-based application has problems sharing
                         under Windows 95. This sets SoftCompatMode=0 in
                         the registry.

   Disable Long Name     This option turns off the tunneling feature,
   Preservation For      which preserves long filenames when files are
   Old Programs          opened and saved by applications that do not
                         recognize long filenames. This option should be
                         checked in the rare case that an important legacy
                         application is not compatible with long
                         filenames. This sets PreserveLongNames=0 in the
                         registry.

   Disable Protected-    This option prevents Windows 95 from terminating
   Mode Hard Disk        interrupts from the hard disk controller and
   Interrupt Handling    bypassing the ROM routine that handles these
                         interrupts. Some hard disk drives might require
                         this option to be checked in order for interrupts
                         to be processed correctly. If this option is
                         checked, the ROM routine handles the interrupts,
                         which slows system performance. This sets
                         VirtualHDIRQ=0 in the registry. (This setting is
                         off by default for all computers in Windows 95,
                         which is the reverse of Windows 3.x.)

   Disable All 32-Bit,   This option ensures that no 32-bit disk drivers
   Protected-Mode        are loaded in the system, except the floppy
   Disk Drivers          driver. Typically, you would check this option
                         if the computer does not start due to disk
                         peripheral I/O problems. If this option is
                         enabled, all I/O will go through real-mode
                         drivers or the BIOS. Notice that in this case,
                         all disk drives that are visible only in
                         protected mode will no longer be visible. This
                         sets ForceRMIO=1 in the registry.

   Disable Write-        This option ensures that all data is flushed
   Behind Caching        continually to the hard disk, removing any
   For All Drives        performance benefits gained from disk caching.
                         This option should be checked only in the rare
                         cases where you are performing risky operations
                         and must ensure prevention of data loss. For
                         example, a software developer who is debugging
                         data at Ring 0 while creating a virtual device
                         driver would check this option. This sets
                         DriveWriteBehind=0 in the registry.

Each option sets a value in the following registry key:

   Hkey_Local_Machine\System\CurrentControlSet\Control\FileSystem

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Keywords          : kbenv kbtool diskmem win95 kbDiskMemory 
Technology        : kbWin95search kbZNotKeyword3
Version           : 95
Hardware          : x86

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