No Windows NT Option Pack Update Information
Unfortunately, I haven't located or received information about any Windows NT 4.0 Option Pack updates that Microsoft has released specifically for Service Pack 6a (SP6a). At this point, we have to assume that there aren't any updates that we need to install.

NT 4.0 Post-SP6a Fixes
QLogic Fibre Channel driver crash. Under heavy system loads, a multiprocessor computer using a QLogic Fibre Channel disk array controller might experience Stop 0x0a blue-screen crashes from scsiport.sys and ql2100.sys drivers. According to Microsoft article Q264247, the stop occurs when the scsiport.sys returns a virtual address that belongs to the QLogic PhysicalCommonBuffer. The article indicates that a stressed system will crash once or twice a week. To eliminate the problem, contact Microsoft Support for a post-SP6a version of scsiport.sys released on May 15.

RAS clients can't reconnect. Many readers have emailed me about RAS clients that can't reconnect after they have established a working connection—and I finally have one possible explanation for the reconnect problem. Microsoft article Q256507 states that if—after a successful RAS logon—you disconnect and then immediately reconnect the client, you might see the error message, "A domain controller for your domain could not be contacted. You have been logged on using cached account information. Changes to your profile since you last logged on may not be available." The problem occurs when the RAS server assigns a new TCP/IP address to the client when the client reconnects. The authenticating domain controller doesn't update its local NetBIOS name cache with the RAS client's new TCP/IP address, so the domain controller can't authenticate the RAS client. There’s a good chance you can fix the RAS client reconnect problem if you call Microsoft Support and ask for the netbt.sys update released on March 2.

Nbtstat problems on RAS servers. When your RAS server has a large number of network interfaces (i.e., 30 or more dial-out lines), you might experience two NetBT-based problems. (NetBT is the driver that manages NetBIOS over TCP/IP connections to and from the local computer.) First, when you run nbtstat.exe from a command prompt, the command won't return any results (except another command prompt). Second, when you run Performance Monitor, you might see Event ID 3101 in the Application Event Log (AEL) with the text "Unable to read IO control information from NBT device." Microsoft article Q259241 indicates that NetBT misbehaves when it reads bindings information from the Registry into an internal buffer and the Registry information exceeds the size of the buffer. The buffer overflow condition is more likely to occur on systems with 25 or more network interfaces bound to NetBT.

The article offers two workarounds for the problem. You can unbind NetBT from all the interfaces that don't require NetBIOS, or you can reduce the number of dial-out lines until you no longer experience problems. To correct the problem permanently, call Microsoft Support and request the bug fixes (a new nbtstat.exe and a new perfctrs.dll) released May 24. The Microsoft article doesn't categorize this bug fix as post-SP6a, so I assume the problem affects earlier versions of NT as well.

HP print driver crashes. Are you seeing blue screens with a stop code of 0x0000000a or 0x00000050 that attribute the problem to HP print drivers? Microsoft article Q262492 indicates that outdated drivers for HP printer models 4500, 8000, and 8001 can cause these system crashes. The article documents a diagnostic procedure you can use to make sure that outdated drivers are causing the problem. To perform the procedure, you must run the pstat.exe tool from the Windows NT Server 4.0 Resource Kit. Pstat.exe displays a list of installed DLLs. If your system has outdated HP drivers that cause such crashes, the list will include a phantom ntdll entry.

Win2K Upgrade Doesn't Convert FAT to NTFS
I recently upgraded several NT 4.0 workstations to Win2K Professional. When you upgrade an NT 4.0 system running on a FAT volume, the upgrade process asks whether you want to convert your boot drive to NTFS. I said yes. However, after the upgrade completed the Win2K Pro install, the boot drive was still in FAT format, and it was clear that the installation procedure ignored the instruction to convert the drive. Microsoft article Q256917 indicates that the Win2K upgrade doesn't convert a drive if you created the original NT 4.0 system using the Sysprep tool. When you upgrade NT 4.0 FAT-based systems you created with Sysprep, you must manually convert the Win2K drive to NTFS using the command convert c: /fs:ntfs after the install completes.

Preparing for SMS 2.0 SP2
To ensure a successful upgrade to Systems Management Server (SMS) 2.0 Service Pack 2 (SP2), you might need to apply two specific updates to every SMS 2.0 site server in your existing hierarchy. Microsoft has released updates that depend on the version of SMS 2.0 that each site is running—two updates for SMS 2.0 (build 1239) and two for SMS 2.0 SP1 (build 1380).

You need to apply these updates if your hierarchy even briefly contains sites within one domain that share logon points. If you're running this configuration, you must apply the updates to all existing SMS 2.0 sites (with or without SP1) before you add any SMS 2.0 SP2 sites to your site hierarchy.

Without these updates, SMS clients might not function properly because the different client component versions can't communicate with each other. Clients can't complete the SMS 2.0 SP2 upgrade process and they can become unmanageable. If this occurs, you might have to visit each SMS client desktop to remedy the situation.

If you run SMS 2.0 without SP1, check Microsoft article Q251070 and Q252718. If you already upgraded to SMS 2.0 SP1, read the instructions in Microsoft articles Q249077 and Q252717.

After you apply the Q251070 or Q249077 update, you must wait until the patch completes the copylog.tcf update on each logon point before installing SP2. Microsoft article Q261931 documents these preparatory steps.