Disabling Video Test at System Restart
Here’s a nifty Registry edit that eliminates the video test Windows NT 4.0 performs when you reboot after updating or replacing a video driver. After you install the new driver, start regedt32.exe, go to the path HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers and delete the keys NewDisplay and RebootNecessary that appear under this entry. This edit lets you bypass the usual dialog box that prompts you to test and set the video refresh rate after you reboot to load the new driver. Microsoft Support Online article Q253296 documents this Registry modification and provides additional references.

NetBt Bug Fix for Multihomes System Connection Problem
If you have systems configured with multiple network adapters and you use an LMHOSTS file that maps system names to IP addresses, the multihomed system might not be able to connect to a remote system. A netbt.sys bug in NT 4.0 Service Pack 5 (SP5) through SP6a prevents multiple network adapters from properly resolving names residing in the LMHOSTS file, even when you include the #PRE directive in the LMHOSTS file. According to Microsoft Support Online article Q253811, you can get a February 20 version of netbt.sys that properly resolves names on all network interfaces. You must contact Microsoft Support for the fix.

SP6/SP6a DNS Changes
When you create a new DNS server, the DNS manager by default creates three reverse lookup zones (0.in-addr.arpa., 127.in-addr.arpa., and 255.in-addr.arpa.). The reverse lookup zones map TCP/IP addresses to TCP/IP names, supply addresses for localhost lookups and queries, and loopback and broadcast messages. DNS manager treats them all as hidden zones.

Microsoft Support Online article Q255880 documents a behavior change in the SP6a version of DNS. Although SP5’s DNS Manager by default displays the hidden zones that it creates, this feature is initially disabled in SP6/SP6a.Therefore, you don’t see the reverse lookup zones—even though the DNS Manager has already created them. If you try to add any of these zones manually, DNS Manager responds with an error message—"The new zone couldn't be created because there is already a zone by this name. Verify that the zone name was entered correctly or choose a new zone name"—and writes an error message with Event ID 1540 in the system event log.

To enable display of the reverse lookup zones that DNS Manager creates automatically, go to the Options menu and check the Show Automatically Created Zones option. Next, right-click the server name, click Update Server Data Files, then right-click the server name again, and click Refresh.

You can also modify the Registry to control the DNS Manager’s behavior. The value entry DisableAutoReverseZones (type REG_DWORD), which resides in the Registry key HKEY_LOCAL_MACHINE\SYSTEM\Ccs\Services\Dns\Parameters, determines whether the DNS Manager creates the reverse lookup zones the first time you configure a DNS server. By default, this value entry doesn't appear in the Parameters key.

If the DisableAutoReverseZones value doesn’t exist or if it is set to 0, the DNS Manager automatically creates the reverse lookup zones with the correct entries (except for a PTR for 127.0.0.1 to localhost). If the DisableAutoReverseZones value is set to nonzero, the server doesn’t create the zones. No GUI checkbox controls this option.

ShowAutoCreatedZones (type REG_DWORD), which resides in the Registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DNSAdministrator\Parameters, determines whether DNS Manager displays the reverse address zones it has created. When ShowAutoCreatedZones is set to 1, DNS Manager displays hidden zones and a zero value suppresses the display. Note that SP5 and earlier service packs set ShowAutoCreatedZones to 1, and SP6 and SP6a set the initial value to zero.

A New Version of Dr. Watson
Have you run the dumpchk.exe utility on the user.dmp crash dump file and seen the message, "ERROR: The module table is corrupt. This dump file is bad"? Apparently, in all versions of NT 4.0 (SP1 through SP6a), Dr. Watson contains a bug that makes it write an invalid dump-file record. Microsoft Support Online article Q255271 indicates that you can call Microsoft Support for a new version of Dr. Watson dated February 25. For more information about dumpchk.exe, see Microsoft Support Online article Q156280.