Q: I am very confused about the meaning and significance of the Service Packs. Can you explain them, please?
Service Packs confuse a lot of people. They contain bug fixes that are cumulative, meaning that Service Pack 2 includes the fixes in Service Pack 1, and so on. For example, the following list contains the bug fixes in Service Pack 2 for Windows NT 3.51.
Q112665: UPDATE.EXE Starts Setup Help if Space Exists in Directory Path
Q128567: Landscape Orientation Reversed with PostScript Driver
Q129670: GSNW Not Releasing Session to NetWare Server
Q129724: Macintosh Client Has Slow Access to Windows NT 3.5x SFM Volume
Q130226: Banner Always Printed When Using GSNW Print Gateway
Q130783: STOP Msg: 0x0000003F NO_MORE_SYSTEMS_PTES Repetitive I/O on MIPS
Q130932: Desktop Remains Active at Logoff
Q130979: User Environment Variables Set Before Default Home Directory
Q131073: Datagram Sends Fail if Route Is Not in IPX Cache
Q131241: FTPSVC Orphans Connections, Uses Up Virtual Memory
Q131428: DHCPADMN Reports Error 14 After You Select Local Machine
Q131689: PostScript Jobs Do Not Print Correctly Over SFM and AppleTalk
Q132085: Applications Hang When Opening Files When CSNW Is Installed
Q132394: Streaming Mode NPMCA.SYS NIC Sleeps on Transmit
Q132511: Windows NT 3.51 Hangs on Shutdown with Some S3-Based Video Cards
Q132722: Server Instability After Reboot Caused by NDIS Driver Problem
Q132896: FTP Client Scripts Terminate Without Completing
Q132903: Err Msg Using NetBIOS over TCP/IP (NETBT.SYS): STOP 0x0000000A
Q133112: NetWkstaSetUid2 API Returns Access Denied
Q133128: Printing from Windows NT 3.51 to an HP4 at 600 DPI Is Slow
Q133252: Windows NT 3.51 GSNW Help Reports the File Is Corrupted
Q133280: FTPSVC: Delay Receiving FTP Directory Annotation and Prompt
Q133303: WINFILE.EXE Application Error When Associating a Searched File
Q133306: Maximum Disk Space of 1.99 GB Displayed for NetWare Volume
Q133384: Event ID 2019: Nonpaged Memory Pool Empty
Q133410: The Breakpoint "\{,
Q133488: LPR Printing Fails After Setting Up Security
Q133701: Forward Slash May Be Ignored as a Path Delimiter in 3.51
Q133757: Performance Monitor SQLServer-Log Object Corrupted
Q134250: No Compaq Netflex Drivers in Windows NT 3.51 for RISC Platforms
Q134285: STOP Msg: 0x0000007B or "0x4,0,0,0 Error" in WinNT 3.51 Setup
Q134286: Windows NT 3.51 Lsar-LookupSids Errors from Big Endian Servers
Q134386: Computers Using QVision Display Driver Lock Up
Q134427: Dr. Watson Access Violation Occurs Sending Mail Attachments
Q134701: Uninitialized Pointers in DHCPSSVC.DLL Cause Access Violation
Q134765: Unknown Software Exception When Application Calls OpenGL
Q134959: Cannot Copy Icons from a Common Group to a Personal Group
Q134968: NetWare Connections Remain Connected After You Log Off
Q134969: Faxing from 16-bit Program Using Separate Memory Space Fails
Q134985: Browsing & Other Traffic Incur High Costs over ISDN Routers
Q134988: Access Violation in glsb-CreateAndDuplicateSection API on PowerPC
Q135065: Windows NT 3.51 Hangs on Shutdown
Q135275: Windows NT Backup: Incorrect Date in "Tape Name" Text
Q135277: WINS Records of Multi-homed Computers Do Not Replicate
Q135291: Print Manager: Owner Appears as System Printing from Macintosh
Q135308: Disk Administrator Corrupts Partitions
Q135471: Cannot Reconnect to OS/2
Name Space Resources on NetWare Server
Q135548: PIF Editor Reserve Shortcut Keys Settings May Be Ineffective
Q135553: IOCTL_NDIS_QUERY_ALL_STATS Causes STOP Msg in Windows NT 3.51
Q135621: NetWare Transaction Tracking System (TTS) Not Detected
Q135667: STOP 1E When Using File Manager and Services for Macintosh (SFM)
Q135692: "List Name From" List Box Shows Only 20 Trusted Domains
Q135724: Deleted Disk Space Not Released on Converted NTFS Volume
Q135774: Performance Monitor Counters Produce Unlikely Results
Q135777: Unable to Connect Using Cabletron EISA F70XX FDDI NIC
Q135856: RIP Table Does Not Update When New RIPX Response Is Received
Q136023: Batch Files Stop Executing with Windows NT Version 3.51
Q136024: Tape Hardware Data Compression Disabled After Running NT Backup
Q136334: Access Violation in LSASS.EXE During User Password Change
Q136336: Windows NT Fails Because of an Access Violation in WINLOGON
Q136375: NTFS Directory Corruption with More Than 100,000 Files
Q136402: IniFileMapping for 16-Bit Windows Apps Fails in Windows NT 3.51
Q136472: NE3200 NIC Driver Can Lose Locally Administered Address
Q136627: Layered Drivers Never See WINSOCK IRPs for the TCP/IP Device
Q136780: WinFax Pro Software Causes 16-bit Applications to Hang
Q136782: Unable to Connect to AT&T Advanced Server for UNIX Printer Share
Should you apply a particular Service Pack? Look at the list, and see whether any of the bugs are relevant to you. If not and if your system is functioning well, I see no reason to apply the Service Pack, particularly on a production machine. Service Packs are not typically regression-tested as other releases are. If you are concerned about a specific application and the Service Packs, ask the application vendor. (For more information see, "Loading Service Packs," in the February issue of Windows NT Magazine.)