5 Reasons Your Computer Is Running Slow

Your computer is running slow–like an old Pentium 2–despite having run lightning fast a year ago. You haven’t changed anything. Your virus checker comes up clean. What happened? This is a common problem that every computer user faces. Before you resort to smashing your computer with a sledgehammer, there are simple steps to revealing why your computer is running slow.

Here are five often-overlooked reasons why your computer is running slow.

#1: Your Computer Is Running Slow Because There’s No Space For The Page File

Have you noticed the huge increases in the amount of computer memory (RAM) shipped with computers over the last decade? My current computer has almost 1,000 times as much memory as my first computer. This is in part a result of greedy programs that want to use as much RAM as they can. If your computer is running slow, having as much RAM as your computer can handle installed, will definitely guarantee that your computer will run faster.

Windows is responsible for distributing RAM to each program. So, what does Windows do when it runs out of spare RAM to distribute? It tells programs to write their least-important memory to a special file on your disk called a page file. As long as there’s enough space in the combined memory and page file to hold every program’s memory, Windows doesn’t have to do anything further.

But, when you run low on disk space because your filesystem is filled up, Windows can’t create a page file large enough to hold any significant amount of program memory. That forces Windows to tell programs that they can’t have all of the memory they need.

Different programs handle low-memory situations differently, but every program must run at least a little slower. Some memory-hog programs, such as modern Web browsers, will run a lot slower when they can’t have all the memory they need.

The solution to this problem is easy: make sure you always leave a little free space on your filesystem. Ideally, you want to leave free an amount equal to the amount of RAM in your computer–so if you have 4 GB of RAM, make sure you always have at least 4 GB free disk space to prevent your computer from running slow.

#2: Your Computer Is Running Slow Because You Have Bad RAM

In at least one way, computers are remarkably like people: we get very upset when we can’t remember something. Bad computer memory (RAM) prevents software (including Windows) from running correctly, so computers spend a lot of time trying to find bad RAM. Modern computers can often work around bad RAM, but the workarounds may significantly slow down your computer–especially if the rest of your RAM is slowly rotting.

There are three times during which you computer can detect bad RAM:

1. Boot up testing runs a very quick test over RAM, plus a more comprehensive check on a tiny bit of RAM used during the boot process. Any bad RAM found here will be disabled until the next time you turn on your computer.
2. Write errors occur when a program tries to write to RAM. All well-written programs programs report these errors to Windows and ask Windows for permission to write to another part of RAM. Windows keeps track of these errors and tries to avoid using that part of RAM again.
3. Read errors are the the worst–they occur when a program tries to retrieve something it previously stored in memory. When it gets an error and realizes it won’t get the data back, the program may crash. Other programs print obscure errors. Some programs may continue to try running and fail minutes or even days later for no apparent reason.

Windows can’t automatically detect read errors, so it will keep assigning the bad RAM to one program after another, possibly making your computer unusable.

All three errors can guarantee that your computer is running slow. Testing and write errors force Windows to keep track of bad RAM (which ironically takes up more RAM) and to assign RAM to programs in smaller, slower blocks. Read errors slow you down by forcing you to recover from program crashes and to deal with strange errors.

How To Fix Bad RAM When Your Computer Is Running Slow?

There is no way to fix bad RAM except by replacing it. What you can do is determine whether bad RAM is causing your problems using a free memory tester. I highly recommend the free Memtest86 program available on memtest86.com. Download the bootable CD image for Windows, burn it on to a CD, and put it in your CDROM drive. At the end of the day, reboot your computer and let Memtest86 run overnight. It will tell you the next morning if it finds any errors. Remove the CD and reboot your computer again to get back to Windows.

#3: Your Computer Is Running Slow Because Your Files Are Fragmented

When you create or save a file, Windows writes the new file starting at the end of the old file. This keeps all the files on your computer’s hard disk close together, but it means that if you increase the size of an old file–say by adding an extra sentence to a Microsoft Word document–Windows needs to split the file into two parts.

Windows hides this split from you–it even hides it from Word–but it still exists. This sort of file splitting is called fragmenting a file.

Fragmented files take longer to load because your hard drive needs to skip around to find each part of the file. You can easily eliminate most file fragments by running the Windows defragmentation tool: from your desktop, open My Computer, right-click your disk and choose Properties, choose the tools tab, and click Defragment Now. It may take several hours to defragment, so we suggest you defragment over night.

To prevent your computer from running slow because of file fragments, we suggest you run the defragmentation tool once a month.

Here is a link to my computer maintenance tips and tricks and my computer maintenance checklist.

#4: Your Computer Is Running Slow Because of Data Cable Cross Talk

You may have noticed that a lot of USB devices take the same cords, but you may not realize that the cords used for high-speed USB disk drives include special hardware to ensure they run at the highest speed possible.