What is Virtual Memory?

Virtual memory is non-physical memory (yeah, like that helps).

Windows uses virtual memory when it doesn't have enough "regular" physical memory to perform a task. When it does this, Windows uses your hard drive to store information that normally would be put into your RAM memory. Here's an overly simplified example:

Let's say you have 1 gigabyte of RAM available and you start launching programs left and right; effectively using up more physical ram that you have available. Things is, that your progrmas are still running just fine! What's happening?

In short, Windows is using a portion of hard drive space to supplement your physical RAM (don't worry, it will be restored once Windows is done with it).

I know what you're thinking. Why bother to add extra RAM to my computer if it can use hard drive space instead? Main reason - RAM is much faster.

Whenever you're using a lot of virtual memory, you're slowing your computer down (way the heck down). The best work around is to get more physical memory. I recommend at least 2 gigabytes or more, depending on how many programs you run simultaneously.