There are a host of software titles out there you can purchase that claim they can speed up your computer. Most of these programs perform basic cleanup and optimization tasks that you can also do with free utilities, such as deleting temporary files, fixing registry errors, and disabling startup items. Periodically cleansing your computer can help increase speed, performance, and stability...but it isn't the best solution in every case. Sometimes you simply need to bite the bullet and reformat your hard drive.
If you want to go the optimization-without-reformatting route, Glary Utilities is one free program that helps you cleanup and optimize your machine. It performs the common tasks mentioned above and more. Once downloaded, you can open it and perform the 1-Click Maintenance, which scans for issues and can automatically repair errors in many cases.
Then you can use the Modules to access other utilities, such as the Uninstall Manager to remove unused programs.
After you’re done cleaning you should run Check Disk, which scans for and automatically fixes disk errors on the hard drive. You should also run Disk Defragmenter, which automatically reorganizes your data on the hard drive for faster operation. Both of these utilities come with Windows and are on the Start Menu: Start > All Programs > Accessories > System Tools.