You can use Task Manager to see how much random access memory (RAM) your computer is using, both at the moment and for the past few minutes.
Open Task Manager by right-clicking the taskbar, and then clicking Start Task Manager.
Click the Performance tab. The bottom two graphs display how much memory is being used in megabytes (MB). The percentage of memory being used is listed at the bottom of the Task Manager window.
If memory use seems consistently high or slows your computer's performance noticeably, try reducing the number of programs you have open at one time, or install more RAM. For more information, see Preventing low memory problems.