What's the Microsoft Browser Service? How do I set up a network with Windows 9x workstations and a Windows NT server running Microsoft SQL Server so that the Win9x machines can see the server and one another? The protocol that loads on boot is TCP/IP, and I'm considering adding a router and attaching systems on the other side of the router to the SQL Server machine.

The Browser Service is a list of available network resources. The four browser roles that networked computers assume are Master Browser, Backup Browser, Domain Master Browser, and Nonbrowser. A Master Browser is a computer that assembles and maintains the list of available network resources. Only one Master Browser exists on the network. The Master Browser assigns Backup Browsers, which are computers that take control of the Browser Service if something happens to the Master Browser. In an NT domain environment, the Domain Master Browser collects Master Browser lists from all the network segments and provides cross-domain browsing capabilities. Only one Domain Master Browser can exist on a given domain on the network. Nonbrowsers are computers that never participate in the Browser Service. Sometimes, computers contend for the Master Browser role. In a mixed NT, Win9x, and Windows 3.11 environment, you need to avoid such competition.

To determine which computers participate in the Browser Service, you can alter the NT registry. Start regedt32.exe in the \system32 directory, and go to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Browser\Parameters registry subkey, which Figure 1 shows. The MaintainServerList parameter, of type REG_SZ, can have a range value of Auto, No, or Yes. If the range value is Auto (the default setting), the computer with this registry entry contacts the Master Browser, which decides whether this computer can become a Backup Browser. If the range value is No, this computer will never participate in the Browser Service. If the range value is Yes, this computer attempts to become a Backup Browser and contacts the Master Browser for a current browse list.

If a Master Browser and a Backup Browser already exist on the segment, the computer won't become a Backup Browser unless the segment has a sufficient number of nodes to require another Backup Browser. (A segment with 1 to 32 nodes requires only one Master Browser and one Backup Browser.) The more nodes a segment has, the more Backup Browsers are necessary. If the computer can't find the Master Browser, it forces an election and becomes a candidate for the Master Browser. Whenever a computer that can become a browser goes online, the Master Browser shares its resources with the Backup Browsers.

If the MaintainServerList value is Auto, the computer might or might not become a browser, depending on the results of the broadcast exchange with the Master Browser. If the MaintainServerList value is Yes, the computer will typically be a Backup Browser. A PDC is always the first to become a Master Browser.

The original NT 3.1 design included a priority for determining which computers became browsers. NT Server systems were first on the priority list, NT Workstation systems were second, and Windows for Workgroups (WFW) systems were third. Today, browser conflicts don't typically occur. However, when conflicts occur, you need to set the Maintain-ServerList registry entry to No on an NT system that you don't want to use as the Master Browser. On WFW systems, you set the following parameter to No in the Network Section of system.ini:

MaintainServerList=<yes, no, auto>

If this value is the default auto setting, the WFW computer functions as a browser.

Don't configure a Win9x machine to be the Master Browser. Go to Control Panel on the Win9x computer, double-click File and Print Sharing for Microsoft Networks, access the Advanced Properties dialog box, select Browse Master, and disable it.

Win95 uses NetBIOS over TCP/IP (NetBT) to connect to an NT server that doesn't use the NetBEUI protocol. With name resolution, you can use the standard syntax \\Hostname\Sharename to connect to the server. Browsing is a NetBIOS-based service that can use NetBT (or NWLink with NetBIOS) if NetBEUI isn't present. To properly browse in an NT and Win9x network, many users need to install NetBEUI.

If you want Win9x machines on the other side of a router to see the NT server when you use Windows Explorer or Network Neighborhood, set up one Win95 computer as a Backup Browser. This computer needs to include a #DOM entry in its LMHOSTS file that points to the Master Browser (usually the PDC) and to a Backup Browser on the other side of the router. You can use an NT workstation instead of a Win9x machine as a Backup Browser for the other Win9x machines. To accommodate name resolution, routers create barriers on remote networks. The only way to overcome these barriers is to use WINS or an LMHOSTS file.

Windows NT displays a warning message that reminds users to change their password before the password expires. Can I change the number of days that NT displays this message?

Before NT 4.0, you couldn't alter the display message's 14-day schedule. However, you can use a registry editor to add a registry entry that adjusts this value. Go to the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon subkey. Add the value PasswordExpiryWarning (of type REG_DWORD). The range for this value is in number of days, and the default value is 14.

What are the arguments in the debate about the mainframe environment versus the client/server model?

Whether the mainframe or client/server model is better depends on how a business uses computers. For example, a mainframe environment is optimal for a hospital running numerous transactions on one database. In this case, the systems administrator develops applications that take full advantage of the mainframe's power, and most input devices are terminals. Mainframe users' business is completely automated, and the users have no need for applications such as Microsoft PowerPoint or Microsoft Word. Yearly support of a mainframe environment is minimal.

My mainframe friends tell me that when you add PCs to this environment without mandatory control (e.g., mandatory profiles), you need to add one support person for every 35 to 50 PCs that you add. The mainframe folks also argue that the constant need to upgrade offsets the low cost of PCs.

The argument for the client/server model is that pools of inexpensive servers can do everything that a mainframe can do but at a much lower cost. In the client/server model, you place multiple servers in an environment and let the clients participate in the workload.

The users in a client/server environment are an integrated part of the computing system. For example, if users are developing PowerPoint presentations, you can set up PowerPoint on their machines. The users can then save their presentations on the server, using it as a file server. This setup works fine and is easy to maintain.

So, which model is better for your business? A mainframe is better in the hospital setting that I previously described; however, the client/server model is ideal for a more dynamic business.

On several occasions, I've had Windows NT systems crash when users run 16-bit applications and the OS doesn't properly update timestamps. What is causing this type of error?

The only factor I can imagine contributing to your problem is the way that NT holds deleted file meta-information (i.e., the file's structures) in cache. Some applications use the file system to hold on to meta-information for a short period so that they can delete, create, or rename an object and still have the original short filename and timestamp intact. When you remove a filename from a directory, NT creates the cache containing the meta-information. When you add a filename, the OS searches the cache. This process is particular to FAT and NTFS when 16-bit applications use files to ensure that the file system retains long and short filenames. Caching the meta-information typically causes no problems, but you can stop caching entirely or change the time parameters by modifying the registry.

Open your favorite registry editor, and go to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\File System registry subkey. To adjust the period that meta-information remains in cache, add the MaximumTunnelEntry-AgeInSeconds value of type REG_DWORD. Set this value to the number of seconds from 1 to 30 (the default is 15). To disable meta-information caching, add the MaximumTunnelEntries value of type REG_DWORD and set this value to 0.