Background programs running:

This is the biggest reason and can be fixed quickly and for free... it's possible that your computer may have so many background programs running simultaneously that there is not enough resources to run normally.

The end result of this is that your computer begins to run more and more slowly over time as you add other programs.

There are two remedies, get Anti-Spyware and use the feature which allows you to view running programs and to disable any of those running programs. Or, if you like to get into your system with your bare hands, use the remedy below.

How to disable unneeded background programs:

All icons in your computers system tray are background programs using memory. There are more, but you will get a hint from that system tray. To see and exit all running background programs:

Windows 95 - ME

a. Press the Ctrl + Alt + Delete keys at the same time.

b. Click any program or task except Explorer or Systray,

c. and then click End Task.

Repeat steps b and c to quit all programs except Explorer and Systray which are necessary components of Microsoft Windows.

You should now have a clean system. See if the computer runs like it used to... if it does, you will want to prevent those programs from restarting the next time you start the computer.

If you don't want any background programs starting when you restart the system, and you know what you are doing, you can run msconfig from the run menu and completely disable what you find in the 'Startup' tab. If you aren't that experienced and you want a safe way to disable all those unneeded background programs, get the remedy recommended for the spyware on this page. It has a feature allowing you to disable startup programs safely.

Windows XP through 2003 Server

a. Press the Ctrl + Alt + Delete keys at the same time.

b. Choose 'Task Manager' tab to view and end any running programs.

c. disabling these programs will require that you change their startup properties in the 'Administrative Tools' area of your system. The Windows Help menu will walk you though that process if you search 'disable programs' in your help section.

Spyware:

Many kinds of software add themselves to your system start menu without even asking your permission. Sometimes you will click on a link or visit a hacker website that installs spyware on your computer without you knowing. NOADWARE is what i use and its free to try.

Fragmented hard drive:

This results from programs being loaded and deleted. Run the Window's hard drive defragmenter (Defrag) once a month. It is under your System Tools menu. Your computer's help menu will tell you how to do it.

Other problems: (Possible, but unlikely to cause problems)

You could have old or conflicting Windows device drivers. An example would be you might actually have two entirely different video drivers on your system and Windows could actually be alternately using both of them.

To prevent this problem, First boot the computer in Safe Mode by pressing and holding the F8 key during startup, after the DOS memory check has completed.

While in Safe Mode select Start/Settings/Control Panel/System/Devices. Click on all the devices and see if the various drivers have any yellow or red exclamation marks (which indicates a driver conflict) and also determine if there are any duplicate drivers that can be eliminated.

You may have to delete and reload a driver to correct these problems. Duplicate drivers can and should be deleted.

As each new Windows program is installed and uninstalled, it leaves behind parts of itself that can slow down or crash your computer. These are mostly .dlls and other shared files.

It's also very possible when uninstalling a program that needed Windows system files can be deleted. When your computer asks if you want to uninstall shared files it's usually safest to say no -- even if your uninstall program claims the files are not being used.

Old Windows drivers can be found by booting into Safe Mode, then opening Control Panel/System/Devices and ridding your system of old drivers.

Otherwise, the only real answer to this problem is to pick up ERROR DOCTOR or just reload Windows into a new directory which eliminates all old junk and leftover files. Reloading Windows is something to do last, as you will also have to reload all your Windows settings, drivers, and programs.

You could be lacking system memory - The only time this may be a problem is if you have an older system and upgraded your operating system without adding some more memory. You should probably upgrade to 256 or 512MB or more of system memory, while it isn't free, it isn't very expensive like it was at one time. Check Tiger Direct to find great deals on memory.