Some Solutions to a slow computer
Upgrade the memory
This is a relatively simple process that many think is difficult. The first thing you need to do if you havent already, is find how much memory you have. For XP users, go to control panel, then select the system icon. You will get a box that pops up that tells you how much memory your system has (among other information). In general, the more memory you have the better. For XP, you should have an absolute minimum of 512 MB or RAM, if you do not, that is the primary cause for the sluggishness of your computer, even if it completely clean of malware. See this link for a basic tutorial on how to install RAM.
In order to determine what kind of memory your system requires check out Crucial. This site has an advisory tool that will tell you how much memory your system was equipped with from the manufacturer, how much more it can take and how many RAM modules you will need to buy and in what combination, if applicable.
Clean the Dirt
Head out to your local Wal-mart, Office Depot or the like and buy a can of compressed air. Take your computer outside, or any well ventilated area. Open the side of your computer. You typically will have thumb screws or regular screws that you take out and a side panel will come off. Generally after a long period of time, you will see layers of dust inside your system. It will look similar to lint you find in a dryer. It is important that you take the computer outside because when you blast this dust away, you will find that it is a very fine dust that goes everywhere. Best to be outside unless you want to clean it up again off of your furniture. Simply blast air off of the components that it has accumulated on. This dust can impact performance as it can hinder proper air flow inside your case. Typically your processor is impacted the most as it may not be able to cool properly. If you are a smoker, this dust may be especially thick.
Hard Drive Failure
This is why it is important that you have a proper backup strategy in place. Some hard drive failures can be predicted and dealt with. Many times you can rescue your data before the drive completely dies. Often the drive dies quickly, in that instance, you may not be able to recover data from it. In this case, a backup can save you heartache and headache. If you have a recovery CD/DVD, replacing your hard drive is simple. Simply install it, boot the recovery disc and you are on your way back to life as normal. If you do not have a disc, you have a problem, but one that can be quickly dealt with.
Easeus ToDo Backup Home or Acronic True Image are two programs that can save you. Both are Hard Drive Imaging programs, Easeus is free, Acronis is not. They will make an exact copy of your system and allow you to copy it to an external drive. If a hard drive starts to die, you can simply take a copy of the drive when it was healthy and copy it to another, new, hard drive. A windows install disc is not necessary because it will simply be using the existing Windows installation present on the dying hard drive.
Registry
One of the biggest scams are registry cleaners. True, the registry tends to be a problem over time, but registry cleaners do not do what they advertise and in many cases, make the problem worse. Windows expert Ed Bott explains why they are bad in this great article. If you must use anything that purports to address your registry issues, use CCleaner. It does all the things that a registry cleaner would do, except it will not screw up your system.
There are other programs you can use that will essentially clean the garbage on your system. You can use Microsoft's built in Disk Cleanup tool. Go to Start-All Programs-Accessories-Disk Cleanup to get to it.
Defragment your hard drive with Windows Disk Degragmenter. It is located in the same Accessories folder as the Disk Cleanup. In Windows 7, defragging your hard drive is automatic each week by default, but you can do it more often if you find it useful.
Unneeded Background Services
For each program you install, it is highly likely that it will install some sort of service in the background. The services installed are intended to help the program you installed with it or it may be an advertisement for some unwanted program. These services take up memory and bog your system down. I had one customer that had so many background services starting that it took her system 45 minutes to boot. She had over 500 services starting. You need to turn off all unneeded services. There are two free solutions that you can choose from
Soluto is a program specifically designed to address the problem of unwanted startup programs services starting on your system. It is free. The utility contains a database of known boot applications and can tell you whether or not it is wise to disable them. In general, the only startup program that should start is your anti virus programs. Most all others are wasting system resources.
CCleaner has a section that will shut off startup programs as well. Open CCleaner and you will see a "Tools" Icon on the left, click on that and you will see for boxes, one labeled "Startup". You will then see all the programs that are designated to start with your computer and whether they are enabled to do so. CCleaner does not give any advice on what you should or should not disable, so you may want to research what is listed to see if it is safe. One tool you can use is a website called Startup. It is a site dedicated to collecting information about every startup program in existence. As of the date of this article, there are 22, 983 entries of startup programs in their database. It will tell you what it is and whether or not it is safe to disable. When you get to the site, click on the database link at the top. You will find a search box on the next page. Simply enter the name of the service and search.
Unused Programs
Quite simply, if you have software on your system that you no longer use or want, uninstall it. Windows has a built in uninstaller, but I would recommend Revo Uninstaller. It does a more complete job at uninstalling programs. When you download, choose the freeware version and not the paid version, of course, unless you want to pay for it!