Fixing computer problems is only as effective and as reliable as your diagnosis of the problem in the first place. Without an accurate diagnosis, you can't hope to effect a proper repair or recovery. It's also true that a diagnosis need not only be an after-the-unpleasant-fact task. Instead of waiting to deal with computer difficulties after they've occurred (what I call pound-of-cure mode), it would be great if users' diagnostics could tell them about potential problems in advance (call it Ounce of Prevention mode).

Windows Vista comes with new diagnostic toolstogether, they're called the Windows Diagnostic Infrastructure (WDI) that not only do a better job of finding the source of many common disk, memory, and network problems, but that can also detect impending failures and alert you to take corrective or mitigating action (such as backing up your files).

Disk Diagnostics

A hard disk can suddenly bite the dust thanks to a lightning strike, an accidental drop from a decent height, or an electronic component shorting out. However, most of the time hard disks die a slow death. Along the way, hard disks almost always show some signs of decay, such as the following:

• Spin-up time gradually slows.
• Drive temperature increases.
• The seek error rate increases.
• The read error rate increases.
• The write error rate increases.
• The number of reallocated sectors increases.
• The number of bad sectors increases.
• The cyclic redundancy check (CRC) produces an increasing number of errors.

Other factors that might indicate a potential failure are the number of times that the hard drive has been powered up, the number of hours in use, and the number of times the drive has started and stopped spinning.

Since about 1996, almost all hard-disk manufacturers have built into their drives a system called Self-Monitoring, Analysis, and Reporting Technology, or SMART. This system monitors the parameters just listed (and usually quite a few more highly technical hard disk attributes) and uses a sophisticated algorithm to combine these attributes into a value that represents the overall health of the disk.

When that value goes beyond some predetermined threshold, SMART issues an alert that hard-disk failure may be imminent. Although SMART has been around for a while and is now standard, taking advantage of SMART diagnostics has, until now, required third-party programs.

However, Windows Vista comes with a new Diagnostic Policy Service (DPS) that includes a Disk Diagnostics tool that can monitor SMART. If the SMART system reports an error, Vista displays a message that your hard disk is at risk. It also guides you through a backup session to ensure that you don't lose any data before you can have the disk replaced.

Memory Diagnostics

Few computer problems are as maddening as those related to physical memory defects because they tend to be intermittent and they tend to cause problems in secondary systems, forcing you to waste time on wild goose chases all over your system.

So it is welcome news indeed that Vista ships with a new Windows Memory Diagnostics tool that works with Microsoft Online Crash Analysis to determine whether defective physical memory is the cause of program crashes. If so, Windows Memory Diagnostics lets you know about the problem and schedules a memory test for the next time you start your computer.

If actual problems are detected, the system also marks the affected memory area as unusable to avoid future crashes. Windows Vista also comes with a Memory Leak Diagnosis tool that's part of the Diagnostic Policy Service. If a program is leaking memory (using up increasing amounts of memory over time), this tool will diagnose the problem and take steps to fix it.

Resource Exhaustion Detection

Your system can become unstable if it runs low on virtual memory, and there's a pretty good chance it will hang if it runs out of virtual memory. Older versions of Windows displayed one warning when they detected low virtual memory and another warning when the system ran out of virtual memory.

However, in both cases, users were simply told to shut down some or all of their running programs. That often solved the problem, but shutting everything down is usually overkill because it's often the case that just one running program or process is causing the virtual memory shortage.

Vista takes this more subtle point of view into account with its new Windows Resource Exhaustion Detection and Resolution tool (RADAR), which is part of the Diagnostic Policy Service. This tool also monitors virtual memory and issues a warning when resources run low. However, RADAR also identifies which programs or processes are using the most virtual memory, and it includes a list of these resource hogs as part of the warning. This enables you to shut down just one or more of these offending processes to get your system in a more stable state.

Microsoft is also providing developers with programmatic access to the RADAR tool, thus enabling vendors to build resource exhaustion detection into their applications. When such a program detects that it is using excessive resources, or if it detects that the system as a whole is low on virtual memory, the program can free resources to improve overall system stability.

Network Diagnostics

Resolving networking connectivity issues has never been an easy task for people who aren't networking professionals. Solutions often entail such arcane actions as "renewing the DHCP lease" and "flushing the ARP cache." Even if you are a networking pro, solving a user's network connectivity and access issues can't be done remotely (by definition) and so requires a visit to the user's desk.

Windows Vista aims to make diagnosing and solving network problems easier with a new Windows Network Diagnostics Tool. This feature analyzes all aspects of the network connection and then either fixes the problem or provides the user with simple instructions for resolving the situation. You can access the Windows Network Diagnostic Tool easily by viewing the connection status from the Network Center, and then clicking the Diagnose button.

Windows Performance Diagnostic Console

Besides the automatic diagnostic tools mentioned in the previous few sections, Windows Vista comes with a new tool for monitoring your system yourself: the Windows Performance Diagnostic Console. You load this Microsoft Management Console snap-in by pressing Windows Logo+R, typing perfmon.msc, and clicking OK.

The console rootPerformance Diagnosticsdisplays the Resource Monitor, which is divided into six sections:

• Resource Overview - This section shows graphs of the data in the CPU, Disk, Network, and Memory sections.
• CPU - This section shows the percentage of CPU resources that your system is using. Click the downward-pointing arrow to expand the section and show the percentage of resources that each running process is using.
• Disk - This section shows the total hard disk I/O transfer rate (disk reads and writes in kilobytes per second). Expand the section to see the files involved in the current disk I/O operations.
• Network - This section shows the total network data-transfer rate (data sent and received in megabits per second). Expand the section to see the remote computers involved in the current network transfers.
• Memory - This section shows the average number of hard memory faults per second and the percentage of physical memory used. Expand the section to view the individual processes in memory, as well as the hard faults and memory used for each.
• Learn More - This section contains links to the Performance Diagnostic Console help files.

The Performance Diagnostic Console tree has three branches: Monitoring Toolswhich includes the Performance Monitor and the Reliability Monitor.

Performance Monitor

The Performance Monitor branch displays the Performance Monitor, which provides you with real-time reports on how various system settings and components are performing. Each item is called a counter, and the displayed counters are listed at the bottom of the window. Each counter is assigned a different-colored line, and that color corresponds to the colored lines shown in the graph.

Note, too, that you can get specific numbers for a counterthe most recent value, the average, the minimum, and the maximumby clicking a counter and reading the boxes just below the graphs. The idea is that you should configure Performance Monitor to show the processes you're interested in (page file size, free memory, and so on) and then keep Performance Monitor running while you perform your normal chores.

By examining the Performance Monitor readouts from time to time, you gain an appreciation of what is typical on your system. Then if you run into performance problems, you can check Performance Monitor to see whether you've run into any bottlenecks or anomalies.

Performance Monitor was called System Monitor in previous versions of Windows, and it has been around for a while. However, Vista's version has a few new features that make it easier to use and a more powerful diagnostics tool:

• If you're using a counter with a significantly different scale, you can scale the output so the counter appears within the graph. For example, the graph's vertical axis runs from 0 to 100; if you're displaying a percentage counter, the Scale value is 1.0, which means the graph numbers correspond directly to the percentages (50 on the graph corresponds to 50%). If you're also showing, say, the Commit Limit counter, which shows values in bytes, the numbers can run in the billions. The Commit Limit counter's Scale value is 0.00000001, so 20 on the graph corresponds to 2 billion bytes.

• You can save the current graph as a GIF image file.

• You can toggle the display of individual counters on and off.

• You can change the duration of the sample (the number of seconds of data that appear on the chart). You can specify a value between 2 and 1,000 seconds. You can see individual data points by hovering the mouse over a counter.

• After a second or two, Performance Monitor displays the counter name, the time and date of the sample, and the counter value at that time. The horizontal (time) axis now has labels that tell you the beginning and end times of the current sample.

Data Collector Sets

A data collector is a custom set of performance counters, event traces, and system-configuration data that you define and save so that you can run and view the results any time you need them. You can also configure a data collector set to run for a preset length of time or until the set reaches a specified size.

You can configure a data collector to run on a schedule as well. For example, you could run the data collector every hour for 15 minutes from 9 a.m. to 5 p.m. This enables you to benchmark performance and analyze the results not only intraday (say, to compare performance at different times of the day), but also interday (say, to see if performance is slowing over time).

Reports

This section holds the reports created by each data collector set. These are .blg files, and you can see the results by clicking the report and then switching to Sysmon view (click the Chart icon in the toolbar). Alternatively, open the folder that contains the report file in Windows Explorer (the default save location is %SystemDrive%\perflogs) and double-click the report file.

Event Trace Sessions

The Event Trace Sessions branch (part of the Data Collector Sets branch) lists the defined sessions for tracing events of various types. In particular, note the sessions named EventLog-Application, EventLog-SECURITY, and EventLog-System. These sessions generate the Application, Security, and System event logs that you see in the Event Viewer.

Event Viewer

Windows Vista constantly monitors your system for unusual or noteworthy occurrences. It might be a service that doesn't start, the installation of a device, or an application error. Vista tracks these occurrences, called events, in several different event logs. For example, the Application log stores events related to applications, including Windows XP programs and third-party applications.

The System log stores events generated by Windows XP and components such as system services and device drivers. You should scroll through the Application and System event logs regularly to look for existing problems or for warnings that could portend future problems. To examine these logs, you use the Event Viewer snap-in, which has a much-improved interface in Windows Vista. You get to the Event Viewer by using any of the following techniques:

• Select Start, right-click My Computer, click Manage, and then click Event Viewer.
• Press Windows Logo+R, type eventvwr.msc, and then click OK.
• Select Start, Control Panel, System and Maintenance, and then click the View Event Logs link under Administrative Tools.

The scope pane offers three branches: Custom Views, Windows Logs, and Applications and Services Logs. The Custom Views branch lists the event views that have been defined on your system. If you filter an event log or create a new event view, the new view is stored in the Custom Views branch.

The Windows Logs branch displays several sub-branches, four of which represent the main logs that the system tracks:

• Application Stores events related to applications, including Windows Vista programs and third-party applications.
• Security Stores events related to system security, including logons, user accounts, and user privileges.
• Setup Stores events related to Windows setup.
• System Stores events generated by Windows Vista and components such as system services and device drivers.

When you select a log, the middle pane displays the available events, including the event's date, time, and source; its type (Information, Warning, or Error); and other data. Here's a summary of the major interface changes and new features that you get when viewing a log in Vista's Event Viewer:

• The Preview pane shows you the basic event data in the General tab, and more specific data in the Details tab. You can toggle the Preview pane on and off by selecting View, Preview Pane.

• Event data is now stored in XML format. To see the schema, click XML View in the Preview pane's Details tab.

• The Filter command now generates queries in XML format.

• You can click Create Custom View to create a new event view based on the event log, event type, event ID, and so on.

• You can attach tasks to events. Click the event you want to work with and then click Attach Task to This Event in the Action pane. This launches the Scheduled Tasks Wizard, which enables you to either run a program or script or have an email sent to you each time the event fires.

• You can save selected events to a file using the Event File (.elf) format.

The Applications and Services Logs branch lists the programs, components, and services that support the standard event-logging format that is new to Windows Vista. All of the items in this branch formerly stored their logs in separate text files that were unavailable in older versions of Event Viewer unless you specifically opened the log file.

System Configuration Utility Enhancements

If you're having trouble during Windows startup, or if you want to try a few different startup configurations to see whether you can eliminate startup items or improve the overall performance of Windows, don't bother trying out different startup configurations by hand. Instead, take advantage of the improved System Configuration Utility, which gives you a graphical front end that offers precise control over how Windows starts.

You launch the System Configuration Utility by pressing Windows Logo+R, typing msconfig, and clicking OK. Here's a summary of the differences you see in the Vista version of the System Configuration Utility versus the XP version:

• The General tab no longer has buttons to launch System Restore or expand a file.
• The tabs for SYSTEM.INI and WIN.INI (those relics of a bygone Windows era) are gone.
• There's a new Tools tab that lists about 15 programs and tools that you can run to troubleshoot startup problems and the system configuration.