Keep your computer running smoothly
Computers tend to respond slower over time; due to variety of reasons.
Cause will not be the same for everyone, but we will try to summarize all common causes, and help you to avoid them.
No disk space
There maybe nothing wrong in your computer but, you don't have enough disk space in your system drive "C drive".
When this happen, the OS will not find a contiguous free space to save all the temporary files that it creates all the time, and will keep rotating the hard disk to save and read the files in different areas in the hard disk. and thus make the computer very slow.
To solve the problem just delete some unwanted files from the hard disk, if you don't know what to delete, then delete all the files in the temp folders in windows, that could be accessed as follow:
Click Start, click Run, type temp and click OK, then delete all the files inside this folder.
Click Start, click Run, type %temp% and click OK, then delete all the files inside this folder.
Logical problem in the hard disk
When you save and delete a lot of files in the hard disk, or when the computer suddenly power down while you are saving or reading some files in the hard disk, the MFT or FAT table could become corrupted or cause a cross link to some files, and prevent the OS or the applications from reading the necessary files for them to work.
This could be easly fixed by running a check disk as follow:
Click Start, click Run, type cmd and click OK, in the command prompt window type chkdsk c: /f and hit enter, because windows already locking the drive it will ask you to schedule the check to run at the next reboot, agree with it and restart the computer to allow it to run.
Because we and the OS tend to create and delete a lot of files on the hard disk, the OS may not find a contiguous free space to save the files and be forced to save the same file in different locations in the hard disk, so when we are in need to read the file, the OS will keep rotating the hard disk to load the file from different locations and cause a performance loss.
To solve this issue just run a defragmentation tool, you can use windows built in defragmentation tool, or get a better one from the internet.
Click Start, click All Programs, click Accessories, click System Tools, click Disk Defragmenter
Choose the C: drive and click Defrag.
Malwares, Viruses, ...etc
One of the most common causes for performance loss is malware infection, like Virus, Trojan horse, crapware, ...etc
They tend to keep the system very busy due to the way they work; they will keep looking for more files to infect or search your hard disk for valuable information or try to steal your bank account info, credit card, email address or whatever they can steal, all these actions will keep the system very busy.
To find how to keep your system virus free please check How to Protect your Computer
Sometimes invalid registry keys point to applications that has been uninstalled or removed from the system, cause the computer to hang or increase the boot time.
There are several utilities in the internet can clean the registry from invalid or unnecessary keys, some of them are free and the other are commercial or free to trial.
One of the best and most reputable software to clean, optimize and boost the computer is Advanced SystemCare PRO.
Finally, if all the steps did not solve the performance issue, you can use dedicated software with advanced tuning features like: System Mechanic