Introduction

Network installations are typically optimised to run single user applications as quickly as possibe. Problems can occur running multi-user applications without taking into account special requirements, such as the disabling of local caching.

This web page summaries the more common issues that arise with various operating systems and possible sources of file and data corruption. It also provided references to other documentation from manufacturers such as Microsoft.

We have not created these problems. Major software vendors have. CAPITAL Office is not the only product that is affected. Products from Lotus, Borland, and hundreds of other software companies may also suffer from these problems and corruptions if they manage databases and are used in a 'busy' multi-user environment.

Please note that we cannot support or repair your network. This issue is between your own business and your network provider. We will, of course, answer questions specific to our products, but we do not pretend to be experts in the dozen different network server products that are commonly available, the dozens of different network protocols and drivers, and the hundreds of different network settings and hardware adaptors.

Windows ME

If you are operating Windows ME connected to NT 4 or NT 2000 consult the sections below for further information on opportunistic locking problems.

See Microsoft Article: Q148367 Possible Network File Damage with Redirector Caching

Windows 95 (95, 95a, 95b, 95c)

1. Apply Service Pack 1.

2. Apply VREDIR update to Version 4.00.1116 or above.

3.  Add DiscardCacheOnOpen setting to Registry.

See Microsoft Article: Q148367 Possible Network File Damage with Redirector Caching

4. Add Load=Spool32 to WIN.INI

Review Spool 32 Errors below.

Certain versions of Win95b contain a faulty redirector system file that returns the wrong information when applications request the file size. For a multi-user database (such as CAPITAL) this could result in overwritten and corrupted data.

MS Document Q174371 (if you forget the "Q" you won't find the Microsoft document) mentions MS Client patch file VRDRUPD.EXE and adding MSWinNT 4.0 Server Registry Setting:  EnableOpLockForceClose=1.  For more information on opportunistic locking problems of NT see the NT 4 section.

VRDRUPD.EXE contains: 

VREDIR.VXD     -  Version 4.00.1116 

VNETSUP.VXD -  Version 4.00.1112 

You can determine how out-of-date the MS Client is by right mouse clicking on each of those files and viewing their version tab information. 

Without addressing these issues, not patching MSWin95 to Rev. B or C, and NT 4.0 to Rev. C or D, will continue to result in network file corruptions, Access Denied (OS Error 5), Network Connection (or Device) Does Not Exist (or Is Not Detected), etc.

The following Microsoft technical articles should also be consulted:

Q130922   AutoDisconnect document

Q124916   EnableOpLocks document

Q129202   Cached Open Limit document

The "time-out" problem if unchecked will contribute to database and other file corruptions, read/write errors, access errors (OS Errors 2 and 5), sharing errors (OS Errors 5, 32, and 83), application failures, etc. The Microsoft and 3Com Websites have further information also describing this as "Network connection (or device) no longer exists (or no longer detected)."

For more information about downloading files from the Microsoft: 

ARTICLE-ID: Q119591

TITLE: How to Obtain Microsoft Support Files from Online Services

Windows NT 4

1. Be sure to apply at least Service Pack 3 or above.

2. Disable opportunistic locking on NT 4 Server.

All versions of NT 4 and above appear to be unable to reliably operate with a c-tree based database "out of the box". The problem seems to be that NT will incorrectly cache local data in order to maximize performance because of its "opportunistic locking" scheme. This scheme appears to be designed to improve performance at the expense of reliability. Opportunistic locking can result in data corruption, particularly if many users are updating the same database simultaneously. (Such a situation would arise if, for example, several users were simultaneously entering and saving invoices.) The following registry settings should be changed to turn off opportunistic locking:

For NT SERVER set these registry keys:

HKEY_LOCAL_MACHINE

System\CurrentControlSet\Services\LanmanServer\Parameters

EnableOplocks = 0

NT CLIENT

HKEY_LOCAL_MACHINE

System\CurrentControlSet\Services\LanmanWorkstation\Parameters

UseOpportunisticLocking = 0

UtilizeNtCaching = 0

UseLockReadUnlock = 0

UseUnlockBehind = 1   // default is 1 but set explicitly for safety

95/98 CLIENT

HKEY_LOCAL_MACHINE

System\CurrentControlSet\Control\FileSystem

DriveWriteBehind = 0  (If not using Novell. However, set this always as it's safer and can't damage anything.)

HKEY_LOCAL_MACHINE

Network\Novell\System Config\Netware Dos Requester

Cache Writes = "OFF"           (only needed if using Novell client)

Opportunistic Locking = "OFF"  (only needed if using Novell client)

Also consult the following Microsoft technical articles:

Microsoft Document Q142803. This reviews locking errors or computer hangs accessing network database files located on an NT 4.0 Server.

Please refer to Microsoft Document Number Q174371, which refers to MS Win95 Client patch, NT 4.0 patches, and adding to the NT 4.0 File Server a Registry Setting such as EnableOpLockForceClose=1.  If these updates are not applied, ALL DOS and Windows applications performing file reads/writes may be adversely affected.

Also: Q174371 for further information and references.

Networking Hardware

3Com also mentions the need to upgrade some network cards by physically replacing older network cards, including those for NOVELL's VLM handling. Corrections to OS Error 55 might include loading the network drivers before a CD ROM device, patching a CD ROM device, disabling "Plug-and-Play" on the 3C509B network card, etc. 

Spool 32 Errors

Some printing problems in Windows 95 and above are caused by faulty interactions between the print spool system and the application performing the printing. As yet Microsoft have not provided a solution or explanation. The typical symptom is that the print job is successfully printed but the application performing the printing doesn't receive correct notification and hangs, or a Spool32 Error message is raised.

Overview

Pre-loading spool32.exe seems to help. This can be done in several ways, but adding it to the WIN.INI is a neat solution. 

Solution (for many cases)

Setup the pre-loading spool32.exe at startup by performing the following steps:

1.        Run SYSEDIT from the RUN command in the start menu.

2.        Select the WIN.INI file.

3.        Change the line "load=" to read "load=spool32". Note: case doesn't matter.

4.        Quit from SYSEDIT and reboot the PC.

Problem Continues

If pre-loading the spooler hasn't solved the problem then you will need to look further.

Microsoft advises that local printers using ECP type printer ports may cause applications to stops responding and hang.  (Refer to Microsoft Document Q141919.)

If the PC uses an ECP printer port and it is suffering spool32 type errors and hanging while printing, then the printer port should be changed to 'normal' mode within the CMOS settings of the PC.

Nortion Anti-Virus

CAPITAL sites have reported problems after installing Norton Anti-Virus software. Some symptoms have included:

	Random crashing when printing
	Very slow network performance

Users should consider completely uninstalling Norton Anti-Virus to see if a compatibility problem exists between it and your PC, which may also affect applications such as CAPITAL.

It has been reported that disabling the software temporarily may not be sufficient to resolve the issue. The software should be completely uninstalled and only reinstalled after it is established that it is not causing the problem.

Tips for Reinstalling Windows

If you are getting constant GPF's (general protection faults) it may be time to re-install Windows.   Make a complete back-up of all important files.   Delete the Windows directory and remove any Microsoft shared directories such as the program files directory.   Reloading Windows by itself may still leave you with many problems. Be sure to reload all the software you need, such as Microsoft Office, etc. Then apply all the necessary patches for your operating system, video card, network adaptor, printer, etc. Be aware that some patches (unfortunately) may also create problems.   Never install Windows over the top of a copy of Windows that is already installed.   You should only need to reformat the hard disk if you believe the hard disk itself has become corrupted. (Use Scandisk to confirm this suspicion first.) Read errors are suggestive of hard disk problems that may require replacement of the hard disk or reformatting.   One of the best sources of patches are the CD's from computer magazines such as PC World, PC Authority, etc.