Note: Before following any of the suggestions in this article it's highly recommended that you have good backup of all your data that has been tested to verify its integrity.
As computers get older, it becomes more and more difficult to get them to run the latest and greatest hardware and software. The newest games are notoriously bad about not running on older hardware. They generally require the fastest CPU, video card, and a ton of RAM in order just to run properly.
Sometimes older computers just don't appear to be running as fast as they use to, or they just stop meeting your needs. When this happens you're faced with the choice of upgrading it, or just replacing it all together.
Before replacing your computer with a new one, there might be a few things that you can do to extend the life of the existing hardware. You might be able to optimize your computer to run more efficiently, or replace/add some new components to meet your needs and get a few more years out of it.
If your computer is running to slow, the first thing that I would recommend is uninstalling application that you don't utilize anymore using the Uninstall a Program Control Panel. After that, run the Disk Cleanup utility (under All Programs | Accessories | System Tools) to purge your system of temporary and used files that you don't need.
It's also a good idea to check your computer hard drive for media and hardware errors. To check the hard drive use the Windows Check Disk utility. Open Windows Explorer, right-click on your C: drive (or what ever drive you want to check), select Properties, select the Tools tab, and then press the Check Now button in the "Error-checking" section of the dialog.
You will now see a Check Disk dialog, you can select the Automatically fix file system errors or Scan for and attempt recovery of bad sectors check boxes, then press the Start button.
Note: The scanning for bad sectors option will significantly increase the time it takes for the scan to complete. You need to download a special tool like CrystalDiskInf to check your hard drive's electronics.
To defragment your drives, use the instructions above, expect press the Defragment Now... button instead of the other button. Press the Analyze Disk button to see how fragmented the data is on your hard drive. Press the Defragment Disk button to optimize your hard drive.
Warning: disabling the wrong start-up program(s) can prevent your applications, hardware, or operating system from working if you don't know what you're doing.
A more advanced system tuning technique is to disable startup applications and/or services that you don't need (use the MSCONFIG.EXE utility). Then use a site like Pacs Portal to help you understand which startup programs are running and what they do.
Also consider running an anti-malware utility to make sure that your system has not been infected by any malicious software. Sometimes viruses or spyware can slowdown your computer. There are several great free utilities for scanning your system for malware, one suggestions is Windows Defender Offline.
Another thing that you can do to try to regain system performance is to backup your data, format the hard drive and reinstall the OS, applications and data. This is not for the faint of heart, because it is a lot of work.
You will basically have to re-install the operating system, application, and all the associated updates. I would recommend that you have broadband access to the Internet to download the system updates.
You might also want to verify that you have the device drivers for all your peripherals (or at least your network card to get access to the Internet). You also want to verify that you have the media and product keys for your operating system and applications so that you can reinstall them.
When To Upgrade
If the suggestions above don't help speed up your computer sufficiently then depending on your computing needs you will need to determine if you should upgrade your existing computer or just buy a new one.
One of the first factors you should consider is the cost and frustration of upgrading vs. buying a new machine. Other things that you should consider are performance, features, capacity, etc.
If the cost of upgrading your existing hardware by adding more RAM, or buying a larger faster hard drive or SSD (Solid State Drive) are considerably cheaper then buying a new computer then you might want to go that route.
Although there is a point where you have to say that upgrading the old computer will not be worth the price vs. the actual performance you will get back in return.
New entry level computers can be inexpensive depending on the hardware that come with the system and sales price. Make sure that when buying a new computer is not comparable to cost of the upgrades.
My general rule of thumb for buying new computer equipment, is buy the fastest, and best equipment you can afford. The most critical part about this rule of thumb, is the last part. Don't go into debt trying to buy the fastest and most expensive components. They will only be replaced with some better, faster, and cheaper parts in a few months.
Note: Depending on the peripherals that you're going to be adding to your system, you might need to upgrade your power supply.