First, it might not be, it might be you. Psychologically, when you buy a new computer, you expect it to be fast, but as it gets older, you expect less of it, and get dissappointed in the performance.
Here are some of the most common problems:
- A virus, spyware, or adware is using you computer's resources.
- Between installations and uninstallations, your systems registry can get corrupted. Additionally, it can get corrupted through normal use.
- System files are damaged due to occasional hard power downs.
- The hard drive is dying and beginning to corrupt your files.
- A weird hardware problem
If you're sure it isn't just you, it might be programs running on your computer. Spyware and adware use your computer resources for their ends, not yours. Before going further, make sure you virus scanner is up to date and run a scan. If you don't have a virus scanner, Avast free edition is, well, free. I'm not getting paid to plug them, but I found their virus scanner to be fairly user friendly and most importantly, free. After you've made sure a virus isn't using your system's resources, there might still be spy/ad-ware on it with a free scanner like AdAware.
Lots of programs use the Windows registry to store their information. With all the changes made to it, it can get corrupted. A tool (again, free) like CCleaner can fix some of these issues.
So you don't have any malware, and your registry is fine, but your computer is still acting weird. If some files got corrupted, there are three reasonable solutions. The easy one, although less effective, is using system file checker. To check system files, go to Start, Run, then type "sfc /SCANNOW" (without the quotes). It will ask you for your Windows CD. Hopefully your manufacturer included one with your computer for a situation like this. If they didn't you can probably find a copy on various websites, or you can call them and ask for one. Even if they won't give it to you, it will let them know that customers want to have this CD. If the system file checker doesn't fix your problem, it's time for more drastic action where you really should back up your data first. Boot from the CD and repair your Windows installation. This replaces most of the files Windows uses. If thing are still screwed up, repeat the process, only reformat your hard drive an reinstall Windows. This is where your backups come in handy.
If your new installation starts acting up or the installer fails, you probable have a bad hard drive, but first, make sure you don't have a dust problem. It's a little rare for computers to be affected by dust, but it's worth checking.
These days, new drives are pretty cheap. For those not technically savvy, picking the right replacement can be a challenge. The two things to look for in a hard drive. First, the size. Laptops use 2.5 inch drives, desktops 3.5 inch. The second thing to look for is the interface. The two main ones are Serial ATA and Parallel ATA. The label on the drive will probably say what the interface is. The general rule is that if the are a lot of pins, it's PATA (also called ATA), if it only has around 10, it's SATA. Be a little careful, though. If you see words like SCSI or fiber channel, it's not a typical consumer hard drive. Armed with this information, browse the internet or a local store for a new drive. If you know what you're doing, get the size that's right. If you don't, aim for the most reasonably priced size, and try to spend between $50 and $100. Once you've purchased and installed the new drive, repeat the Windows installation.
If you're still having problems, here are some things to remember about old computers:
- Sometimes, they don't play well with new hardware.
- Don't spend much more than $100 to fix it. At that point, just get a new one.
- You might just need more memory. For Windows XP, 256mb is a reasonable minimum, but 512mb really helps.
- If you're hearing strange noises, the parts that are supposed to make noise are the hard drive, CD-ROM drive (when in use) , CPU fan, and power supply fan. Strange noises are a bad sign, and you should try to replace the part.
This isn't exhaustive. There are unusual things that can happen. Sometimes, CPUs, motherboards, and RAM die, but all of these are solid state, so death usually occurs later. I have a Pentium 2 system that's over 8 years old and still works fine, except everything other than the CPU, motherboard, and RAM has been upgraded.
I didn't explain the details on how to do some of this as there are numerous guides out there already. I mainly wanted to explain why your computer that worked fine when it was new is now sluggish.