We are still in an economic crisis, and many people are still without jobs. Is it possible to spend hundreds of dollars on new computers? The answer is that most of us probably can't. However, look at these five inexpensive ways to upgrade your existing computer for better overall performance.Upgrade Your Hard DriveA hard drive can typically go bad after about 2-3 years, so replacing it will help your computer improve performance and run faster. You can typically get a 500 gigabyte hard drive for around $125-$150 depending on where you shop.Add More MemoryYour computer's performance will be better if you add more memory. Crucial.com is a website that can run a scanner to find out what kind of memory you have and how much of it. If you have less than 2 gigabytes, you might want to think about adding more memory. The cost per gigabyte is typically $40, which is very inexpensive.Clean Your Hard DriveAfter a few years, your computer will become slower. Consider purchasing an external hard drive that you can plug into your USB port. In a few hours, all of your files will be backed up, and your computer will be as good as new since you won't have all of those files bogging it down.Switch MonitorsIf you have an older desktop, you probably have the older monitor that came with it. Purchase a new flat-panel monitor and you'll be able to watch DVDs and be more productive by being able to have more than one program constantly in view. A new monitor is actually pretty inexpensive - search for arefurbished one and save even more.Leave it to the GeeksThe Geek Squad can drive over to your home and help you if you believe these technological devices are not your strong point. The Geek Squad typically charges $50 to install a drive, which is pretty cheap. Make sure to reload software yourself though, since the Geek Squad will charge you an arm and a leg.