Uninstall last program installed. Many times, new programs introduce problems onto your system. See if the problem goes away by uninstalling the last program installed. Always uninstall by using the Control Panel "Add/Remove Programs" or the program's own uninstall utility. If your PC has been "acting up" for a while, then you may have too many recently installed programs for this to help isolate the cause (or even remember which programs were installed last). Also note it is a very good practice to reboot before and after installing new programs or games (regardless if prompted to or not by the program).
Remember what you've recently run. A previously run program can be the culprit, so keep track of the programs you've run since booting. Once I was helping someone with a computer that was constantly locking up and crashing. I asked about recently installed programs, but the user insisted that the problem was happening "everywhere" in her system (when browsing, editing, reading e-mail). After some investigation, we discovered a common thread: The system became unstable after a particular game (that she liked and played often) was run. The system would continue running after exiting the game, but eventually lock up or crash. Eventually, we found an update (patch) for her game and the problem was solved. This type of problem can be even more insidious if the program in question isn't one you run manually but runs automatically or in the background (like FAX software and items on your taskbar). We'll discuss these types of programs more in a later step.
Run Scandisk and Anti-Virus. If you're this far into troubleshooting, you've probably already done this. However, it needs to be mentioned. Be sure to get the latest Virus definitions from your anti-virus vendor.
Check Disk Free Space. The more current your version of Windows and applications, the more free disk space is required. It is not uncommon now to need at least 300 to 400 free megabytes of space on the C: drive for computers to run properly. Delete any unnecessary files from your hard drive. If you're tight on space, also consider "hard setting" the values for the sizes of your Temporary Internet cache (IE, Tools/Internet Settings) and your system swap size (Control Panel/System/Performance/Virtual Memory). However, the best practice is to operate with adequate disk space.
Clear out Cache and Temp files. If you don't have a program like Norton Utilities doing this automatically for you, consider manually cleaning out your c:\windows\temp folder, your Temporary Internet folders (use Internet Explorer Tools option on the menu bar and select "Internet Options" to delete temporary files and cookies). It's a good idea to reboot and run scan disk after cleaning out files, particularly when you do it manually.
Check safe-mode Device Manager for duplicates. Boot into Safe-Mode on your computer by tapping the F8 key during boot. You'll be shown a menu from which you can select "safe-mode". Once in safe-mode, go into the Control Panel and double-click on "Systems". Go to the Device Management tab and expand all the entries. Look for duplicate entries for the same device. If you find any duplicate devices (by the same name, or the same device listed by two different names), then delete ALL the entries for that device and let Windows redetect the devices. You should remove all duplicates until you can boot into safe mode and not see any duplicate devices. Also check for and remove duplicate entries under the modems icon in Control Panel.
Obtain the latest drivers. Go the web sites of the hardware manufacturers and get the latest drivers for all your hardware (video card, sound card, network card, etc.). Don't forget to check for BIOS updates for your motherboard and system updates (i.e. PIIX). If you run any special peripherals (graphics tablet, memory reader, USB devices, cameras, etc.), update the drivers for those as well. Always look on the vendor's website first for drivers. You can also find drivers at locations such as www.drivershq.com or www.windrivers.com (a subscription based service).
Obtain the latest patches. Go the web sites of the software you run on your system and get the latest patches and updates for all your programs. Also go to the Windows Update page and get all the Product Updates for your version of Windows. In my experience, doing all of the above fixes the problem in the majority of cases. (Don't worry, more suggestions follow).
Norton Utilities (WinDoctor). Norton Utilities 3.0 and above have a very good diagnostic program called Norton WinDoctor. This program will analyze your system and help fix the most common registry problems. For the novice, there is a "one click" fix that does a very good job. This product is also sold under a bundle called "Norton SystemWorks". In my opinion, it is the single best tool for keeping computers running smoothly. If you're having problems with you Windows PC, get this software! It does a lot of good things automatically and quite safely.
Check for known conflicts. It's not unheard of for a software package or hardware component to have a conflict with other hardware or software. For example, the Microsoft Picture It! graphics editor had a known conflict with the drivers for some HP printers which would cause the system to lockup. Check on the websites for all your main hardware components and peripherals. Look for any known problems with software or hardware you may have on your system.
Remove network card. An ill-configured or ill-running network card can cause some of the strangest problems ever seen on a PC. If you have a network card in your system, go into Control Panel and double-click on "Network". Record all your settings before you temporarily remove the network card from your system.
Turn off power management. Go into your system BIOS and turn off power management. You can usually get into your BIOS setup screen by pressing F2 or the "DEL" key during boot.
Check startup folder and icon tray. Look in the startup folder under the Start Menu, Programs and temporarily remove any non-essential "startup" programs. (You can remove or move items in the Startup folder by right-clicking and choosing "open" on the start button). Also look in the icon-tray on the taskbar and disable or shutdown as many background programs as possible. Usually, it's a good idea to make a new temporary folder and move the items in your startup folder rather than delete them (so that you can put them back in later!)
CTRL-ALT-DEL and check contents. Under Windows 95/98/ME, when you press the CTRL-ALT-DEL, a task list will pop-up. Check and compare what's running in your task list to what is normally running on your system when not having problems. You might spot a particular program running that's not usually there, or something new. If you don't know what your system was running before you had problems, you can also look on another PC to compare. Go to PCmagazine.com and checkout their utilities in the download section. Search for, find, and download a utility called "End It All". The Enditall utility is great little tool that provides a "one-click" option to close all but essential processes on your PC. It's fantastic for this type of troubleshooting.
CTRL-ALT-DEL and end all processes. You can also try ending all tasks except systray and explorer in the task list. If your system quits giving you problems, then you need to look in the startup folder, icon tray, win.ini, and registry "run" items (see below) to stop or remove all unnecessary programs from running when your computer starts.
Check autoexec.bat and config.sys. Sometimes new programs will make automatic entries in your startup files. Remove or remark out any lines that run programs you don't recognize. Be sure to make a backup copy of each file first.
Check for programs started in win.ini. The file win.ini in the c:\windows directory contains a "run=" and "load=" line. Remove or remark out with a semi-colon (;) any programs started in the win.ini.
Registry "run" items. If you don't already have it installed, use the Control Panel "Add/Remove" Windows components and install the Policy Editor. (Click the "Have Disk" button and browse to the Win95/98 Install CD and look in the Admin/AppTools/Poledit). After Policy editor is installed, you can open the Policy Editor under "Programs/Accessories/System Tools" and open the registry. Check the "Run" items in the System section under Local System. This will contain programs which are started when Win95 is started (similar to the run= line in the win.ini file). You can also edit these items directly by using the regedit utility and browsing to:
\HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
In the CurrentVersion section, you will find several "Run" folders containing programs that are automatically run each time you start Windows. In the registry editor (regedit) you can export the current section you're looking at to a .reg file. You can use this as an easy-to-restore backup. If you export each "run" section, you'll be able to remove entries and start without those processes running. You'll also be able to double-click on the .reg files to restore those sections to the original value!.
Run Msconfig. From Start/Run, type in msconfig. Depending on the version of Windows, this tool can tell you a lot about what is being loaded and running on your system. In the newest version, it can also perform an automatic "cleanup" for certain areas to remove obsolete items from being loaded. It also has some options that can help you troubleshoot by elimination (i.e. not loading certain items when booting).
Add RAM. Swap out your RAM, and if possible add additional memory to your system. Faulty or insufficient memory can cause strange problems on computers.
Upgrade Power Supply. Now this sounds weird, but I've seen on more than one occasion a flaky power supply cause strange problems, lockups, and crashes on a system. This may be a job for you to take to a local computer store or vendor. It depends on what you're comfortable with. Modern (more recent) systems use an ATX power supply connector which makes the connection much easier for the novice.
Redetect Devices. Remember the troubleshooting step earlier where we removed abnormal devices from the Device Manager? This step goes further. This time, remove all the components from the Control Panel, System, Device Management screen. Reboot the system and let Windows redetect and add only those devices which are actually on your system.
Remove cards. Sometimes the source of odd problems can be from faulty or conflicts between components. Try removing all the cards from slots in your computer (sound cards, capture cards, network cards, modem cards, etc). Leave only the minimum required cards (i.e. the video card). If the problem still exists, repeat the "Redetect Devices" step above with all possible cards out of the system. If the system runs normally (outside of the things you can't do with the cards removed) then your problem may be a faulty card or a conflict with cards. Add them back in one at a time and test to see if the system remains stable.
Rerun setup (no overwrite). Run the setup and do a "soft reinstall" of Windows 95/98 (run setup off the Win95/98/ME CD or your c:\windows\options\cabs folder). During the installation, you'll be prompted whether to overwrite "newer versions" of files on your system. Do not overwrite any newer files which already exist on your system.
Rerun setup (overwrite). If the "soft reinstall" did not work, run the setup and overwrite all files. This will put you back at the "factory versions" for all your operating system files. This may cause some programs to quit working. so you'll need to reinstall some programs.
Reinstall the major "mainstream" applications. You need to do this especially if you've reinstalled Win95/98/ME in the "overwrite" method described above. Programs like Microsoft Office, Microsoft Project, and other mainstream Windows 95/98/ME programs will not only implement themselves into the registry and setup, but they will typically put the latest versions of the program libraries and support files back onto your PC.
Rebuild the PC (Operating System). This is a drastic solution, and it is not for the novice user, but if all else fails, consider rebuilding from scratch (repartition and format the hard drive). This is a fairly advanced task. Be sure you have all your drivers, documents and files backed up. Also be sure to have your Windows media and required serial numbers.