Which Windows file stores RAM contents on disk when physical memory is full?

• A. memory.dmp
• B. hiberfil.sys
• C. swapfile
• D. pagefile.sys

Answer: (D)

When Windows runs out of physical RAM, it uses virtual memory to keep running by moving less-active data from RAM into a reserved area on disk called a page file. The file that stores these swapped-out pages is pagefile.sys, located on the system drive. This paging mechanism lets the operating system free up RAM for current tasks while keeping the swapped data readily retrievable when those pages are needed again.

Other files have different purposes: memory.dmp is created to capture memory contents after a crash for debugging, hiberfil.sys stores the entire RAM contents to disk to enable quick resume from hibernation, and swapfile is not the standard Windows page file name.