How to Fix an Unstable Computerby Jason Artman ; Updated September 28, 2017
An unstable computer that frequently crashes or shuts down is more than an annoyance to use; it can destroy data and hinder productivity. Instability is caused by your computer's hardware or software. If you eliminate the potential causes from least to most difficult, you can fix your computer while expending minimum effort.
Install an anti-virus program to check for viruses and malicious software. A virus can cause a computer to behave in unpredictable ways, and if your computer has suddenly become unstable when it previously worked with no problems, a virus may be the cause.
Use the Windows System Restore function. This will restore your computer to a previous state if your computer has become unstable after you made a change, such as installing new software or device drivers.
Install a program that scans for and repairs problems in the Windows registry. As you install and remove programs, the registry can become large and full of invalid entries referencing programs that no longer exist. A registry repair tool can resolve these issues.
Remove software that you no longer use. Numerous programs that you install run automatically and consume system resources. If you have several programs installed, the shortage of system resources may cause your computer to slow down or lose stability.
Resolve any issues that may cause your computer to overheat, such as dirty or malfunctioning fans, blocked vents or improperly seated heatsinks. When a computer overheats, it may slow down, crash or shut down without warning.
Back up your important data and reinstall Windows if you are unable to improve the stability of your computer through troubleshooting. Reinstalling Windows reverts your computer to the original factory state, which should resolve any software issues. If your computer remains unstable, you may need to replace one of its components, such as a hard drive or CPU.