Having a slow computer is not something most users fancy, but that is what most of us end up with after prolonged usage despite having the latest hardware. Understandably, there are also a few of us who are trapped with a low-end PC and are forced to get as much out of it as possible. This article caters to both these type of users as it not only explains how to make your computer as fast as it was when new but also how to reduce the footprint of your system to utilize your PC's current system resources in the best possible way.

First thing first. Make sure your PC isn't infected by a virus, worm or other malware

Anyone who has used an infected computer will verify how painfully slow a computer becomes when infected by a virus. More tech savvy users will counter that an infected computer's speed depends upon the type of malware. To be honest, it does. However, based on my personal experience, I can say that while some malware are designed specifically for making computers slow and unresponsive, most malwares tend to decrease a computer's performance. 

If your computer is infected, the first thing you need to do is deep scan your entire hard drive to remove all traces of the virus. Also, scan your secondary storage devices to make sure that they are clean as well. Additionally, make sure to follow best security practices to avoid getting infected in the future.

Remove unused and unnecessary programs

Now that we are sure that your computer is not slow because of a virus, you need to get rid of all the unnecessary programs that you have installed on your PC. To remove these programs, go to Programs in theControl Panel and uninstall your unnecessary programs one by one. If you are like most Windows users (including me) and are having a tough time figuring out which programs to uninstall as all of them seem important, follow this rule: If you have not used the program in the last month, it probably is unnecessary. It is better to uninstall that program given that you can reinstall it whenever required. It also is a good idea to remove all the useless software that came bundled with your computer. If you want, you can remove unused Windows features as well to further tone down your operating system.

Try faster alternatives to your everyday programs

If you use applications that require too much computing power to operate, you are better off replacing them with applications that do the same job as them but faster. Few resource hogging applications that you can replace are:-
1) Most resource intensive antivirus software can be replaced with the lightweight Microsoft Security Essentials.
2) Microsoft Office can be replaced with OpenOffice, an open source alternative that also has loads of amazing additions.
3) Adobe Reader can be replaced with the free Foxit Reader.
4) The newer versions of Internet Explorer (IE 10 and above) are less resource intensive. If you have been using an older version, it is time to upgrade IE or replace it with either Mozilla Firefox or Google Chrome. This will also give you faster internet speeds.

Remove unnecessary startup programs

Startup programs are the programs which start automatically each time a user logs on. Not only do they result in a slow startup, but they also run persistently, until you close them manually, continuously consuming valuable system resources (CPU and RAM) while they are running. So, disabling unnecessary startup items results in both a faster startup and a more responsive computer, as these applications not running continuously means more RAM and CPU will be available for the operations you perform on the computer.

To disable unnecessary startup programs, type msconfig in the search bar in Start menu (in Windows 10,Windows 7 and Windows Vista) and on the Start screen in Windows 8 and 8.1. On Windows XP, type this in the Run dialog box. This will start the System Configuration utility. Click on the Startup tab and disable all the applications that you think are not essential on your computer's startup. Restart your computer to see the changes. Keep in mind to not disable your security products as that will make your computer more susceptible to getting infected.

Restart your computer often

This is assuming that you continuously use your computer for long periods of time. Each time when you close a running program in Windows. it frees the memory that the program was occupying. However, it may so happen that some parts of the memory do not get freed which results in less system resources available to you to use which ultimately results in a slower PC. When you restart your computer, these occupied spaces in the memory get freed. Although, this memory issue has been somewhat fixed in recent versions of Windows, it still is a good idea to reboot your computer at least once a day.

Check your hard drive for errors

Over time, as you use your computer, chances are that some errors might creep in your hard disk which negatively affect your computer's performance. The best way to solve this issue is by using the inbuilt Disk Check utility available in all versions of Windows. To use it, execute chkdsk /r in the Command Prompt. Remember to open the Command Prompt as an administrator. It might prompt you to restart your computer. Execute Y to restart your PC. The chkdsk/ r command scans your computer's hard drive for errors and recovers readable data. Depending upon the size of your hard disk, this step might take some time. This step might increase your computer's performance phenomenally if there are a lot of errors on your hard drive.

Make sure you have enough free space

System speed is not only dependant upon CPU and RAM. If your hard drive is above 95% full, you will notice that your system hasn't been running at the fastest speed. This happens because Windows require empty space for swap files to increase in size and also as space for temporary files. It is imperative that the more cluttered and filled a hard drive is, the more difficult it is to read. To solve this issue, delete unnecessary data or move it to external storage devices.

Repair protected Windows system files

As you use your computer, it is possible that one or more system files get damaged or get corrupted which might effect your system's performance in a negative way. Thus, it is important to check that all your system files are original and behaving as they should. The best way to check your operating system's files is through the System File Checker. To run the System File Checker, open Command Prompt as an Administrator and execute sfc /scannow. This command will check all your system files and if it finds that some of them are modified or corrupt, it will replace them with the original. This step can take anywhere between 5 to 15 minutes but is one that you should perform especially if your system has ever been infected by a virus.

Disable unnecessary visual effects

The visual effects that make your computer look beautiful also slow it down considerably. So, if you want to get the best performance out of your computer, you should disable all these visual effects. To disable these visual effects:-
1) Press Windows Key+R to launch the Run dialog box.
2) Execute sysdm.cpl.
3) Go to the Advanced tab in the following Window and click on Settings in thePerformance section.
4) Then encircle Adjust for best performance. If you want to use visual styles and themes, check it (located at the very end of the list).
5) Click on Apply to apply the changes.

Disabling these visual effects could lead to a considerable improvement in your system's performance especially if you are on Windows 7 or Windows Vista and using the Aero interface without a graphic card.