In the Windows environment, the system memory acts as a temporary storage for applications. When an application is executed by the user, it pulls out relevant library files from the hard disk and loads them into the system memory where the data is consumed periodically. When system memory is run out, Windows uses a part of the hard disk as a virtual memory to store the data which spilled out of the physical memory. But Virtual memory can be quite slow compared to the physical memory, and therefore it can slow down the system. However, if the user didn’t assign enough virtual memory to the Windows, it might end up crashing.