Hmm, I guess you're the one who doesn't understand. There's certainly some info on the internet where you can look up how virtual memory works in detail, but here it is in short:

The virtual memory handler is part of the Windows kernel (not of WED). Virtual memory consists of physical memory plus a hard disk space that you've reserved (or not). Windows first uses the physical memory, and then when running out of it begins to swap memory pages to the hard disk.

All programs on your computer use virtual memory for storing their data, and terminate (or crash) when running out of it. Thus it was a bad idea to disable your hard disk allocation for virtual memory.