For your computer and it’s applications to run smoothly your computer must have sufficient amount of memory installed. Windows XP must have a minimum of 64 MB of memory installed, however that is not nearly enough. Microsoft recommends a least 128MB, and 512 for your computer to run at a optimal level. If your using any kind of graphic intense program such as photoshop or if your are into gaming, 512 MB or more is absolutely critical. If you are running Windows 98 you can run 128MB of memory.
Your computer uses its memory in three different variations, physical memory, RAM, and virtual memory. The use of virtual memory is the amount of disk space that you have on your hard drive. Windows uses that disk space to supplement RAM memory. However virtual memory is not nearly as efficient as RAM memory because RAM memory is feed directly to the CPU.
Click Start --> All Programs --> Accessories --> System Tools --> System Information --> Now you can view the Total Physical Memory, Available Physical Memory, Total Virtual memory and the Available Virtual memory.

