Why does my computer run so slow?
When you first got your new (Windows) computer, not only was it shiny and fresh, but it seemed to run as fast as can be. Now that you have been using it for a while, maybe a few years, everything seems SLOW! Opening programs, closing programs, running programs, accessing the internet, all seem to take much longer than they did before. This is a very common "cry for help" in the computer consulting business. Often frustrated users want a quick and simple answer, not a long-winded technical explanation about why this is happening. Why does the so-called "expert" have to spend hours looking at your computer to solve this problem? If there really were a quick and easy answer, your expert would be sure to tell you, unfortunately, this is not the case. There are many different reasons why a computer can turn "slow", and any of them (most likely a combination) could be the cause of your own problems. Some time needs to be spent reviewing what is going on in your system to get it resolved. The good news is, in the majority of cases, your computer can be "sped up" to it original condition by making some configuration changes. Sadly, there are probably many many computers that are purchased today that are bought for the sole purpose of replacing a perfectly good computer that has become "slow". This is not a very good solution, first because the original computer may be perfectly good enough to do the work required of it with good speed, and second because the new computer will more than likely eventually slow down because of all of the same reasons!
Just as there are many reasons why a computer can turn slow, there are many ways to try to troubleshoot and resolve the issue. Here are some steps that can be taken in approximate order, although really they can be done in any order.
Make sure the hard drive(s) are not too full
Its a good idea to check this first. Filling up any hard drive (but especially the main drive where Windows is installed) on a Windows computer to near capacity is a very bad idea, and this will certainly cause the computer to slow down to a crawl. The used capacity of each hard drive is easy to check in a number of ways, for example, by launching the File Explorer and right-clicking the drive and selecting Properties. The drive should NOT be approaching full, in general, anything over 80% full is not a good situation. The operating system needs that empty space in order to efficiently operate. With today's large multi-gigabyte hard drives, its a good idea to have at least 1 gigabyte as open space.
If any hard drive is getting too full, then some information must be removed from it in order to get things back in order. This can be done by simply deleting unwanted files or uninstalling unneeded programs. Or, information can be moved onto another hard drive that has more available space. If the situation is such that all of the information is needed and there is no more hard disk space, then you will be faced with either replacing the hard drive with a larger one or adding another hard drive to take up some of the load.
See if excess programs are loaded in memory
Your computer's internal memory, or RAM, is also limited in size and it can become too "full". In this case, it is running programs that cause this. As time goes by, most likely there will be more and more software programs that are installed on your computer as you try different things, purchase new software, and so forth. Many of these programs will automatically load themselves into your computer's memory every time your computer starts. If your RAM memory gets too full, you will definitely get an overall slowdown of the computer. Many of these programs do not actually need to be running all the time, taking up space in memory; they can be disabled from automatic loading and still easily accessed when they are needed. Unfortunately, once again there is no "easy way" to just fix the problem. You need to analyze all of your running programs by accessing the Task Manager and determining what programs are being loaded and which ones can be disabled.
Check for a rogue program that is hogging CPU cycles
Sometimes even a legitimate program can become locked into some sort of loop and keep running in the background when it shouldn't be. This "hogging of CPU cycles" will definitely slow down everything. A quick way to test this is to open the Task Manager and check the CPU Usage meter on the performance tab. If you are not doing anything with the computer, in other words its basically in idle mode, the CPU Usage should be basically zero or very close to it. If the CPU usage stays consistently high, then move to the Processes tab and look down the list and try to identify the rogue program, which will have a number much bigger than zero un the CPU column. This program needs to be stopped, and either removed from the system or reinstalled so that it behaves properly.
Check for overheating
Overheating is a fairly common cause of computer slowdowns. If the internal temperature of the computer near the CPU gets too high, the CPU will automatically slow itself down to prevent it from becoming damaged, and the result will be an overall slowdown in performance. This is typically caused by a build-up of dust inside the computer and especially around the cooling fan intakes or outakes, and it can occur in both desktop and laptop computers. Luckily this is usually easy to fix by blowing out all of the dust with compressed air (this can me a messy process). For laptop computers the vents can be located on blown out, and for desktop computers the covers can be removed for easy clean-out access.
Check for malware - viruses, worms, spyware, etc.
Any sort of malware contamination is likely to cause an overall slowdown in computer performance. The basic rules of computer protection as seen here should always be followed to prevent infection. Any time a computer is seemed to be "too slow", it should be subjected to a complete virus scan and anti-spyware scan to make sure that everything is clean.
Defragment the hard drive
While there may be debate as to whether frequent hard drive defragmentations (or defrags) need to be run, it is something that should be done at least once in a while. This might mean once or twice a year. If you want to do it more often it certainly won't hurt. But if a Windows computer is run for several years with no defrags at all, the information on the hard drives will become so scattered that the hard drive access times will slow down to a crawl, which in turn will slow the whole computer down. Take some time occasionally to run the disk defragmenter, which can be found in the Start menu under Accessories/System Tools.
Conclusion - a series of relatively simple steps can "speed up" your slow computer
There is no "fast and easy" way to diagnose and repair a computer that has become "habitually slow". A methodical approach through the steps outlined above has a good chance of producing success in the form of a much speedier overall experience. Most computers that have been sold in in previous years, while certainly not as fast as the new ones being sold today, are easily fast enough to accomplish the basic tasks that the majority of home computer users need to do - such as checking email, surfing the internet, writing basic documents, etc. While it is true that you will get a faster overall experience if you purchase a new computer, it really may not be necessary. You may be able to "resurrect" your current model by these simple clean-up steps and save your money for other technology such as a bigger monitor.