I'm going to assume you use Windows. Here a couple of free utilities that actually help instead of pushing ads or paid versionsn1. thing I ever found. Install it run a scan. If you're running it for the first time the scan should estimate a large amount of data. Clean it. It will empty your Recycle Bin and browser history and click on Registry. Scan and clean. I don't ever take backups when asked simply because I've never faced problems. 2. O&O Defrag FreenDownload and install download 32 or 64 bit as your OS. Analyse all drives defragment if they're above 1%.nAlso download PageDefrag to defragment locked files like your pagefile. DO NOT BOTHER WITH THIS IF YOU USE A SOLID STATE DRIVE 3. Uninstall unnecessary programs! VERY of the time you may have installed that crappy toolbar that got in your way instead of helping you and you never got rid of over to Control Panel and then Programs. Uninstall all of it and remember to check off the next one thates (CCleaner might prompt you to install one). 4. Get rid of bloatware ( software with too many extras) . nMost people usually pirate huge software only to use about 5% of it's features. Here are some popular bloatware programs that you might find on your PC with alternatives.n Adobe Reader. De facto software used everywhere. But really heavy.n Replace with Foxit Reader.n WinRAR. This isn't really bloatware but I find 7-Zip doesn't clutter your right-click con Explorer - if you still use it move on! Google Chrome is a nice This really popular software now has about 8 or 9 utilities when you probably installed it just to burn data to CDs. Use Nero BurnLite. Light and Office I prefer OpenOffice because it's free and almost the same. Or LibreOffice. For my usage anyway. 5. Reinstall Windows!nAny geek will tell you a hard format is THE best way to get your PC feel like it's running on steroids. In the end any OS will require a format and the better managed ones will only need formatting after a longer time (I reinstall Windows on my PC every 8-1 months inspite of doing everything mentioned above).nNo formatting does not mean you will lose all of your data! I mean yes it will wipe out the partition you formatted but remember you need to format only the partition you're reinstalling Windows on usually C. Take backups of files on your desktop and Documents. And download your drivers before you do so (DOWNLOAD them afresh don't just hunt for your supplied CD because drivers are frequently updated and they have performance and critical security enhancements). One secret to avoid installing unnecessary programs Don't take backups of your installed programs. Wipe out Windows and reinstall. Now download and install whatever you NEED as opposed to what setup files you have You'll be surprised to find you didn't need half the software you had. Install only when you remember a program you'll actually use.