Using File-System Troubleshooting Options

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

Important

Enabling any of the file-system Troubleshooting options will seriously degrade system performance. Typically, you want to enable these options only if instructed to do so by your product support representative.

To display the file-system Troubleshooting options

  1. In the System option in Control Panel, click the Performance tab.
  2. Click the File System button, and then click the Troubleshooting tab.

The following table summarizes the settings in Troubleshooting properties. Each option sets a value in this Registry key:


Hkey_Local_Machine\System\CurrentControlSet\Control\FileSystem

File system option

Description

Disable New File Sharing And Locking Semantics

This option alters the internal rules for file sharing and locking on hard disks, governing 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 with sharing under Windows 95. This sets SoftCompatMode=0 in the Registry.

Disable Long Name Preservation For Old Programs

This option turns off the tunneling feature, which preserves long filenames when files are 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-Mode Hard Disk Interrupt Handling

This option prevents Windows 95 from terminating interrupts from the hard disk controller and 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=1 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, Protected-Mode Disk Drivers

This option ensures that no 32-bit disk drivers are loaded in the system, except the floppy 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-Behind Caching For All Drives

This option ensures that all data is flushed continually to the hard disk, removing any 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.