How To Clean Up a Slow PC

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This article details the various reasons a PC may be running slowly and explains how to speed up a slow PC.


Why Your Computer is Running Slowly

Not having enough RAM is a major cause of computer slowness, followed closely by the buildup of temporary files on your hard disk. A PC that is infected with a virus or does not have enough hard disk space for the files on it are other causes. Finally, a disabled Direct Memory Access could cause a computer to run more slowly that usual.

What to Do When Your Computer Is Running Slowly

Deleting temporary files, defragmenting the disk space, and updating your operating system are some of the ways you can increase the speed of your PC. You can also try checking for viruses on your computer and getting rid of any that you find. Finally, you can look into upgrading your computer's RAM.

How to Know if Your Computer Has Enough RAM

RAM stands for Random Access Memory and is used as temporary storage memory by your computer. This memory is in use when tasks are being executed by different programs. You should have enough RAM memory to process all the tasks at hand. If you don't, this can cause a major slowing down of your computer while it is booting up or processing tasks.


Hardware can be just as guilty as software for slowing down a PC, although more often than not software is blamed. The programs installed on your computer usually have specified RAM requirements. If your computer was been running at normal speeds before the installation of certain programs, and has since slowed down, you might need to add more RAM on your computer system. Also, if your computer slows down every time you are processing large files, or it freezes while performing several actions at once, you might need to add extra RAM.

Temporary Files Have Built Up on Your Hard Disk

Some tasks might require you to leave the system working for several days. This might cause temporary files to build up on your hard disk and may be why your computer has slowed down.


Cleansing your temporary files, including your internet history — including cookies — gives you a larger amount of hard disk space to work with.

How To Delete Temporary Files in Windows 10

To delete temporary files in Windows 10, search for Disk Cleanup from the taskbar and choose it from the list of results:


Under Files to delete, select the file types that you would like to get rid of. If you would like a description of the file type, simply select it. When you are done, select OK to save your changes:


Emptying Your Recycle Bin

When you're done, go to the Recycle Bin on your desktop, and choose Empty Recycle Bin:


Deleting Your Temporary Files

You can also choose to delete the temporary internet files that have accumulated on your system. Go to the Start button, and open Control Panel. Select Internet Options, and in the section labeled Temporary Internet Files, press Delete Cookies > Delete Files.

Deleting Your Internet History

You can also delete your history by clicking the option Clear History.

When done, press Apply > OK.

Defragmenting Your Hard Disk in Windows 10

Another way to speed up your computer is by defragmenting your hard disk, which gathers dispersed and lost space in order for it to be used by the computer again.


Launch the disk optimization tool by searching for defrag in the taskbar:


In the window that opens, select your hard drive and click Analyze:


In the results list, check the percentage of fragmented files. The recommendation of how fragmented your disk should be is under 5%. However, there is no rule for this and you may choose to follow a different standard.

If you would like to defragment your disk, click Optimize. When the process is finished, your percentage of fragmented files should be at 0.

How To Delete Temporary Files in Windows XP

Open My Computer, and select your local drive. (It is usually labeled as C:\\.) Select the Windows folder, and locate the folder labeled Temp.

Use your mouse to right-click on the folder (not the contents), and in the View options, choose Details. Select all the files that are older than the current date, and press the Delete key on your keyboard.

When you have finished removing the temporary files, reboot your computer.

Your Computer Has Been Infected

If your computer has been infected by a virus, malware, worm, or Trojan, it might cause the system to slow down and even freeze several tasks. We recommend that you post your issue on the CCM Forum Virus/Security section, where you will receive assistance for your individual case.

Not Enough Space on the Hard Disk

Adding very bulky programs will automatically slow down your computer system. Users with a hard disk capacity of 2 GB need to leave at least 250 MB free, and those with a higher hard disk storage capacity need to leave at least 20% of the total capacity free. This will allow your computer enough room for both temporary files and file swapping.

Your Direct Memory Access (DMA) Is Disabled (Windows 7)

The Direct Memory Access will allow data transmission between your hard drive and CD drive without requiring the microprocessor's intervention. Those using Windows XP will not have this option set by default.


To manually enable it, click the Start > Control Panel > System > Hardware > Device Manager.

List the ATA/ATAPI options by clicking the + icon next to it. Select Primary IDE Channel, and in the Primary IDE Properties window, select the Advanced Settings tab. Check whether the Transfer Mode for Device 0 and Device 1 enable DMA. Click OK to confirm the changes

Click Secondary IDE Channel, and in the Secondary IDE Properties, select the Advanced Settings tab. Check whether the Transfer Mode for Device 0 and Device 1 enable DMA. When done, click OK to confirm the changes.

Update Your Operating System

Having the latest Windows updates will not increase system performance. However, patching up any security loopholes or performance-related glitches may be beneficial. In the long run, your system will be better off with the latest OS updates.

Compressing Infrequently Used Files

The files that you don't often use can still take up quite a bit of disk space on your computer. For files created using Microsoft's NFTS system, you have the option to compress your drive files (under the General section on your hard drive). When you activate this option, your files will be more or less compressed based on how often you use them.

Removing Dust from Your Computer

It is recommended that you completely remove the dust from your computer's main unit at least once per year in order to prevent the overheating of certain elements, like the computer's cooling fans.


Before doing so, unplug your computer completely remove the power cord to be sure that the electricity is cut. Wait roughly fifteen minutes before beginning the cleaning, as a rapid change in temperature can cause damage to your main unit.

When cleaning the device, using a can of compressed air made specifically for this purpose is the safest bet. Still, be sure to follow the instructions on the can to be sure not to accidentally spray liquid on your computer. Note that it is not recommended to use a brush for this job, as you could damage the fragile parts of your main unit.

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