Many of you may have older computers running Windows XP and may find that they are getting a bit balky. Before considering putting them out to pasture you can do a few things to keep them serviceable for your older applications that might not run on Windows 7.
I service about 40 XP Professional computers at a small private school with a "careful" budget that does not allow for many new equipment purchases. Here is some of what I do--and you can, too,--to keep the older equipment running as smoothly as possible:
1. Check the amount of RAM that you have. 512 MB is the minimum, in my opinion, to keep you from becoming frustrated when using Windows XP, although it will run on less. Your computer's user guide will tell you the maximum memory that your computer can handle. Then you can go online to a reputable dealer that sells memory. The major companies will guide you through the selection process since it can be a bit tricky to find exactly the right RAM for your upgrade.
2. Check how much free space is left on your hard drive. Whenever your RAM is not enough to run a program your computer will use free space on the hard drive to "swap" programs back and forth into RAM as needed. If you have programs that you don't use any more you should uninstall them to free up space. If you have a lot of photos, videos, or other media stored on the drive you may wish to consider moving them to DVDs or to an external drive. If you have an older computer with a really small drive you can also delete some of the Windows uninstaller files.
3. Check your Recycle Bin, System Restore, and Internet Options to see how much space is allocated to files. Again, this is particularly important for smaller capacity drives on older computers.
4. Use a third party program such as CCleaner (free) to clean clutter, optimize the registry, and manage your startup programs. The latter is often a culprit in a computer's slow performance. Many programs do not need to start when Windows starts, nor do they need to sit in your System Tray all the time just "waiting". Of course, your antivirus/antispyware program and firewall need to start and run all the time.
5. Speaking of antivirus and other security software, be sure that your computer meets the System Requirements for running them or they will greatly slow your computer down as they are protecting it. Some programs are what are called "resource hogs" so if you are not happy with how your computer is responding when they are running you can look for something else that is less demanding on your resources. Only run one antivirus/antispyware program and firewall at a time (more will only slow your system to a crawl) and be sure that you scan periodically for malware.
6. Hardware problems can cause a slow response, too, but they may not be readily evident. You should check the inside of your case at least once a year to clean out dust since excessive dust will cause overheating and component degradation. While inside, check the capacitors to be sure that they are not leaking. This was an industry-wide problem that affected computers for a few years in the early 2000s. A computer can run with a failing capacitor or two but it will most likely give you trouble. Hard drives can be checked via software from the drive's manufacturer but Windows has a tool called Error Checking that can help you, too.
These tips are just to get you started. With a little TLC your older XP computer will serve you well until Microsoft's "sunset date" in 2014. If you need details about any of the procedures you can post a question on this forum.