How to clean up hard drive?

Find how much RAM you have. The amount of virtual memory you set up is going to be proportional to how much RAM you have. To find this number, right click "My computer" and then "Properties." Under the "General" tab you'll see toward the bottom how much RAM you have. An example of what you might see here is, "504 MB of RAM."

Go to your virtual memory settings now that you know how much RAM you have. Click the advanced tab. You'll see a box for "performance." Click "settings," then the "Advanced" tab. In the box near the bottom it says "virtual memory." Click "change."

Set how much virtual memory you want. The way to figure this out is to set both the minimum and maximum as 1 and 1/2 the amount of RAM you have. So if you have 504 MB of RAM, choose 761MB for the minimum and 761MB for the maximum. Why put both the same? Well, your computer will start flip flopping between using your virtual memory and RAM as you open and close programs, and this can cause it to lag more. If you find that you don't like how this works out after you try it, you can always backtrack using the steps above to set it to the defaults. So don't worry, this isn't permanent.

Try this out. If you still don't have enough virtual memory, or if you found that your virtual memory is already set at 761 (or a different number that you calculated based on your RAM) you have 2 options to deal with a virtual memory error message. Either run fewer programs at the same time, or upgrade your RAM. This is a hardware installation, and it requires taking your computer in for service, either with the computer manufacturer, or to a retail store that has a service center. Just check your warranty to make sure this sort of upgrade does not void your warranty. Good luck!