Service Pack 2 Caveat Emptor

Caveat emptor

The irony about service packs for Windows NT is that they oftenbreak as much as they fix (for an illustration of this point, see Mark Minasi, "Recoveringfrom a Network Disaster"). You can attribute this phenomenon to Microsoft'srefusal to put service packs through the same rigorous external testing phasesthat general release software goes through (read: Microsoft won't beta test thefixes). This approach isn't good.

Microsoft recently released Service Pack 2 (SP2) for NT 4.0, which fixesmany nagging bugs in the operating system. You can get more information aboutthe fixes from the Service Pack 2 Information Center athttp://www.winntmag.com.

SP2 Fixes
With one major fix, symmetric multiprocessing (SMP) users can now run NT 4.0on a computer with more than four processors without the computer periodicallygoing south. SP2 also fixes NT 4.0 so that it replicates data properly from aPrimary Domain Controller (PDC) to a Backup Domain Controller (BDC).

When you install SP2, the setup program asks whether to save uninstallationinformation. I strongly suggest that you do--the process takes about 6MB of diskspace, but you won't have to repair your NT system if the service pack causesproblems. The uninstall process is a bit messy (for example, you have to savethe uninstall information on your system partition), but having the option is astep in the right direction.

Surprisingly, Microsoft also added two new API calls to NT 4.0, using SP2as a delivery vehicle. These two calls, ReadFileScatter() and WriteFileGather(),let programs pull in data from an uncached file and store it in a discontiguousbuffer, and vice versa. They also give disk I/O-intensive applications such asSQL Server and Internet Information Server (IIS) a serious performance boostbecause you can now move data from memory to disk in one pass.

SP2 Bugs
You're probably wondering where the irony comes in. Well, SP2 is quitepossibly one of the most problematic service packs I've installed to date--mysystem was infinitely more stable before I installed SP2. The bugs range fromamusing and anecdotal (SP2 breaks Point-to-Point Protocol--PPP--connections intoThe Microsoft Network's online service) to downright deadly (SP2 can scrambleNTFS partitions to the point where you can't read them anymore). At press time,Microsoft had acknowledged some of the bugs in SP2, promised imminent hotfixesfor some, and made some hotfixes available on ftp://ftp.microsoft.com.The available hotfixes address some of the issues listed below, such as theRemote Access Service (RAS) bugs, and are probably easier to implement thantheir respective workarounds. You can get more information on the hotfixes fromthe Service Pack 2 Information Center, which is updated as new information andhotfixes are available.

To find out how real users are getting around these problems, I went onInternet Relay Chat (IRC); the following paragraphs describe SP2 bugworkarounds, courtesy of the folks in the #windowsnt channel on the EFNet IRCnetwork.

If you use a virus scanner that stays active in memory (such as McAfeeVirusScan and Symantec's Norton AntiVirus), chances are you've seen the bluescreen of death (BSOD) when you write data to a floppy. The fix is to set thevirus scanner's services to start manually in the Control Panel. A hotfix forthis bug should be available by the time you read this article. However, if oneisn't available, Microsoft recommends turning off auto-protect or on-the-flyscanning features as another workaround.

SP2 has also led to problems with RAS connections. For example, Dial-UpNetworking on SP2 seems to search for multilink capabilities to connect to anInternet Service Provider (ISP). If your connection fails, open the RegistryEditor and drill down to the HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Rasman/ppp key and create a new subkey called DisableMultilink.Give it a hexadecimal value of 1, and reboot the system.

Along the same vein, RAS in SP2 has problems connecting to ISPs that useAscend routers. Dial-Up Networking completes the connection, but you end up witha dead link. To restore PPP capability, uninstall SP2 and replace raspppen.dllin the SP2 installation directory with the original file from the NT 4.0 CD-ROM.Then reinstall SP2. Alternatively, you can grab a hotfix fromftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/nt40/hotfixes-postSP2/ras-fix that patches the system to fix the bug.

Some NT systems crash with a BSOD if you insert an autorun-enabled CD-ROM.The workaround is to disable autorun. Drill down to HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Cdrom in the Registry and setthe Autorun value to 0. You'll lose the autorun functionality, but it beatsseeing the BSOD every time you insert a CD-ROM. If you're vigilant enough, youcan leave autorun enabled but hold down the shift key each time you insert a newCD-ROM.

Some users have also reported seeing their CPU pegged at 100 percentutilization. Thus far, this problem seems to affect only machines with a PlextorCD-ROM drive. If you have this problem and have a Plextor CD-ROM drive attachedto your computer, just insert a CD-ROM in the drive and NT will be usable again.

Finally, the most serious SP2 bug scrambles NTFS partitions. Before youstart seeing "Cannot access drive" errors, uninstall SP2, replace thentfs.sys and advapi32.dll files in the SP2 installation directory with theoriginal files from the NT 4.0 CD-ROM, and reinstall SP2.

From my vantage point, the lack of a proper beta test prior to release hurtthe quality of SP2. If SP2 fixes something that's been bugging you (no punintended), you should install it and see how it goes on your system. If SP2causes more problems than it's worth, I suggest you do what I did--uninstall itand wait for SP3.