SANtools, Inc.
Utility that monitors the disk hardware with the goal of identifying disks that have a strong possibility if crashing. Supporting, Windows NT/95/98/2K/ME (Intel-based) running SCSI, Fibre Channel, SSA, or IDE disk drives.
http://www.santools.com/index.html

Ultra-X, Inc.
Hardware and software tools for PC diagnostic and troubleshooting. Products include PHD, PCI, and QuickTech Pro.
http://www.uxd.com/

BelAsset
PC hardware and software discovery in your web browser. Freeware and corporate licensed versions.
http://www.belarc.com/BelAsset.html

#1-PC Diagnostics Company
Developer of PC diagnostics tools. #1-TuffTEST runs automatically or can be scripted. #1-TuffTEST-Pro is menu-driven for complete and precise testing control. Both are operating system independent and self-booting. A free feature-limited version is also available.
http://www.tufftest.com/

Micro 2000 Inc.
Software, hardware and training materials for PC diagnostics, troubleshooting and repair. Micro-Scope or Microscope PostProbe and training A+ certification courses.
http://micro2000.com/

CDi Communications, Inc
PC Sentry Check Kit includes program and board for troubleshooting dead PCs.
http://www.netwind.com/html/diagnostic_tools.html

CST Inc
DocMemory PC Memory Diagnostic is a stand alone program. CST Inc also makes hardware memory testing systems.
http://www.simmtester.com/

3B Software
SANDRA Pro is benchmarking and diagnostic program. [Windows 95/98/ME/NT/2000/XP]
http://www.3bsoftware.com/

Data Depot Inc
PC Clinic diagnostic program. Hardware tools also offered.
http://www.datadepo.com/indexstart.htm

Expodata Systems
Company provides quality diagnostic hardware and software for PC manufacturers, maintainers and IT departments. Products include the SIMCHECK memory tester for DIMMs and SIMMs and PCTESTPRO diagnostic kits.
http://www.pctestpro.com/

System Analyser
Detects and provides information about all computer hardware. It also provides benchmarks of the processor, memory, hard disks, CD-ROM and the video adapter.
http://www.sysanalyser.com/

Memtest86
Free memory test program for x86 (PC) computers. Stand-alone diagnostic program that fits on one bootable floppy. Linux and Windows versions available with source code.
http://www.memtest86.com/

ScanCD
ScanCD checks your CD for unreadable files.
http://scancd.pisem.net/

BenchmarkHQ
Archive and news site for benchmark and sysinfo software.
http://www.benchmarkhq.ru/

Touchstone Software
Company develops innovative problem-solving software for pinpointing computer problems.
http://www.touchstonesoftware.com/

Field Service Tools
Software and hardware diagnostic and test tools for the field service professional. SCSI, Fibre Channel, IDE, and USB analyzers and testers.
http://www.fieldservice-tools.com

CDRoller
CD media analysis tool and tester, complete analysis, diagnostic and test of file system and disk surface under Windows 95/98/ME/NT/2000/XP.
http://www.cdroller.com/

x86 diagnostic tools
Free or Open Source diagnostic tools for the x86 platform.
http://www.robertwrose.com/diag/

PC-Doctor, Inc.
Developer of PC diagnostics and system information software, provides diagnostic software to OEM PC manufacturers and service and support professionals.
http://www.pc-doctor.com

PassMark Performance Test
Hardware benchmark utility to assesses computer performance.
http://www.passmark.com/products/pt.htm

Micro2000 Inc.
Offers PC diagnostic toolkits and complete solution suite application Micro-Scope and Burn-In and RemoteScope for networking administration solutions.
http://www.micro2000uk.co.uk/

Smith Micro Software
CheckIt series of PC diagnostic programs.
http://www.smithmicro.com/checkit/

Windsor Technologies, Inc.
Manufacturers of PC diagnostic software products for PCs. Products include PC-Technician, PC-Diagnosys and The PC Toolbox Newsletter.
http://www.windsortech.com/

DisplayMate Technologies
Publisher of the DisplayMate utilities for testing, evaluating and improving image and picture quality for CRTs, analog and digital LCD monitors, video projectors, HDTVs, televisions, plasma displays and micro displays.
http://www.displaymate.com/

TestLAB 2003
TestLAB 2003 is a system utility for Windows to analyze, benchmark, check and optimize your PC.
http://www.testlab2003.com

busTRACE Technologies LLC
A professional software bus analyzer that captures and analyzes I/O activity going on between your Windows PC(98, 98SE, Me, 2000, XP) and its storage class peripherals Supports IDE, ATAPI, ATA, Serial ATA, SCSI, USB, USB 2.0, 1394, Fibre Channel, and RAID.
http://www.bustrace.com

Millennium Solutions
Provides info on the micro2000 PC Diagnostics Software and Hardware and Computer Training courses. Learn to build, repair, maintain and diagnose problems with computer hardware.
http://www.millennium-solutions.co.uk/

PC Certify Diagnostic Software
PC Certify Diagnostic Software provides advanced system and device configuration reporting, quick tests,diagnostic testing for Computer Repair Technicians
http://www.pc-certified.com

American Megatrends Inc.
AMIDiag Suite is a PC diagnostic utility that offers a complete answer to system administrators, service technicians and end-users. The Suite includes both the Windows and DOS PC diagnostics programs. News, downloads, support, and product upgrades.
http://www.amidiag.com/

SCSI Toolbox, LLC
iSCSI, SCSI and Fibre Channel analyzers and test software.
http://www.scsifibretest.com/

Uniblue - WinTasks
Diagnostic (tasks and memory) utility for Windows
http://www.liutilities.com/products/wintaskspro/

Eurosoft (UK) Ltd.
Personal, corporate, and military PC diagnostics and data security solutions: PC Builder, QA+FE Service Centre, QA+WIN32, Pc-Check, ZeroData, Virtual Pc-Check, Virtual QA, CD-Check, PCI/ISA POST Board and other test accessories.
http://www.eurosoft-uk.com

Utility Software
ModemChk makes it easy to check the results of your last connection, for reconfiguring your modem, comparing results, and checking line noise. Click the auto detect button or use the command line options to open and run an AT command of your choice.
http://www.utilitysoft.co.nz/

HDD Temperature
A disk utility that monitors the current temperature of hard drives to prevent data loss. Available in English and German.
http://www.hddtemp.com/

Visual SCSI Explorer
Testing of SCSI devices under Windows 2000. Visualization of SCSI host configuration. Manual and scripted (JScript, VBScript) command execution. Optimized for Medium Changer SCSI devices.
http://www.scsiexplorer.com.ua

Sysinfo Lab - ASTRA32
Performs computer configuration analysis, and provides detailed information on computer hardware and its working modes. Includes product development history, mode screen displays, support links and product download page.
http://www.astra32.com/

Hot CPU Tester
A burn-in stability tester to tests all components for intermittent errors.
http://www.7byte.com

The Zen and Tao of Diagnostics
Articles about diagnostics and embedded systems design.
http://www.ganssle.com/articles.htm

SourceQuest Inc. - SourceUSB
USB analyzer for USB firmware, hardware, and driver developers. Targets Windows platforms and USB 1.x and 2.0.
http://www.sourcequest.com/

PC Bug Doctor
Offers free software download to scan a PC for errors. PC Bug Doctor will fix all types of windows errors.
http://www.pcbugdoctor.com

PC Diagnostic Utilities
PC diagnostics and system information software, provides diagnostic software to OEM PC manufacturers and service support professionals.
http://www.pc-diagnostics.com

Reseller
for Micro 2000 and other diagnostic and data recovery products
http://www.lovemyprices.com

Memtest86+
Free memory advanced diagnostic utility based on the original Memtest86.
http://www.memtest.org/

Winstress
PC software diagnostics tools and utilities.
http://www.winstress.net/

Everest
Free diagnostics and benchmarking program running on Win32 platforms. Display information on the screen, print it, or save it to file in various formats like HTML, CSV or XML.
http://www.lavalys.com/

CD/DVD Diagnostic
CD-R Diagnostic tests, examines and recovers data from CD, CD-R, CD-RW, and DVD discs.
http://www.infinadyne.com/

SpeedFan
Monitors fan speeds, temperatures and voltages. It can access S.M.A.R.T. information and change fan speeds based on system temperatures, thus reducing noise and power consumption.
http://www.almico.com/speedfan.php

Tabernus, LLC
Specializes in SCSI, iSCSI, Fibre Channel, SATA, SAS, and related diagnostics and testing.
http://www.tabernus.com/

x86test
bootable x86 CPU detection and reporting. Displays lots of information about processor including very accurate clock and FSB timings, cache configuration etc., open-source license
http://www.vortex.prodigynet.co.uk/x86test/

Serial Port Monitor
Professional application for RS232/422/485 COM ports monitoring. It monitors, displays, logs and analyzes all serial port activity in a system, tracks down problems in system or application configurations and processes.
http://www.eltima.com/products/serial-port-monitor/

SysNucleus - USBTrace
USB bus analyzer for Windows.
http://www.sysnucleus.com/

MemMXtest
A free (GPL) advanced memory tester that runs on any MMX PC.
http://www.opensourcepartners.nl/~costar/memmxtest/

Linux EDAC Project
Project to extend Linux ECC support beyond /proc/ram to full error correcting.
http://bluesmoke.sourceforge.net/

Test My Hardware
System information and diagnostics utility that provides detailed information about hardware components.
http://www.testmyhardware.com

TestNext Software and Services B.V
Forms2test is a performance test solution for predicting system behavior and performance of Oracle Forms applications. With forms2test you can obtain an accurate picture of end-to-end system performance and identify performance bottlenecks before go-live.
http://www.forms2test.com/

SuperMonitor
Adontec offers a protocol monitor and serial protocol monitor software. The software also supports monitoring on Notebooks.
http://www.adontec.com/smon_e.htm

BCM Advanced Research
System analysis utility that helps you diagnose problems on PCs running Microsoft's Windows operating systems. Also provides a native DOS diagnostic program
http://www.bcmdiagnostics.com

RAMspeed
Free open source cache and memory benchmark for UNIX-like and DOS\Windows systems.
http://www.alasir.com/software/ramspeed/

USBlyzer
Software USB protocol analyzer that decodes the USB device descriptors and captures and analyzes I/O requests for USB devices in real time.
http://www.usblyzer.com/