The amount of time you spend on your computer and the amount of testing and experimenting with new software you do would determine how often you should do maintenance. If you do not have these programs you can Google them. They are all free. If you do not have these set to run as scheduled tasks they should be run first and if problems are found they need to be resolved. Windows Security Essentials Windows Defender *** Then every week or month run these: Make sure your windows Update is running and shows no errors - type Update and view History. Programs and features.... remove any software you have evaluated and decided you don't want to keep Autoruns - check over everything that is loading when your system starts and pay close attention to anything NOT from Microsoft in the Services and Scheduled Tasks. If you have a 3rd party program that optimizes the registry and compacts it and backs it up, use it when you do your routine maintenance. Cclean - Clean temp files (and has a feature to Optimize Registry) Run this command to back up the registry - "regedit /E c:\RegistryBackup.reg" Back up your work folders, images you have added and software you have downloaded and want to keep. Run: SFC /scannow (from a command prompt) - and let it check/repair/verify your system files NOTE: If you have copied the Internete Explorer folder from \program files (x86) to "\program files" in order to "trick" Windows 64 bit to use IE 32 bit in order to view flash media (YouTube) and Silverlight viedo files, SFC WILL RESET your modifications. Defrag - if you use the Windows packaged defragger, remember it has an option to run on all drives with one command. Reboot and enjoy! Every few months run True Image and make a bootable clone of your system on another hard drive.