Virtual Memory Pagefile Registry Location

In Microsoft Windows, the active configuration for system-wide virtual memory paging files (pagefile.sys) is managed directly through specific registry entries. This article identifies the exact registry path, the multi-string values that define paging file distribution across drives, and how Windows interprets these size and location parameters.

The Active Registry Path

The active configuration for virtual memory paging files is stored under the following key in the Windows Registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management

Primary Registry Values

Inside the Memory Management key, Windows uses the following values to configure and track paging files:

• PagingFiles (REG_MULTI_SZ):
  This is the primary value that dictates the user-configured or system-managed distribution of pagefiles. Each string entry within this multi-string value represents a separate paging file configuration formatted as:
  [Path] [Initial Size in MB] [Maximum Size in MB]

  • System Managed: If a drive is set to automatically manage pagefile size, the value is stored with 0 0 for the sizes (e.g., C:\pagefile.sys 0 0).
  • Custom Size: If fixed sizes are allocated, the explicit megabyte values are listed (e.g., D:\pagefile.sys 4096 8192 sets a 4 GB initial size and an 8 GB maximum size).
  • Automatically Manage All Drives: If Windows is configured to automatically manage the paging file size for all drives, the entry contains ?:\pagefile.sys.

• ExistingPageFiles (REG_MULTI_SZ):
  This value is populated by the Windows kernel during boot to track which paging files are physically mounted and actively in use by the operating system session.

Applying Changes

Modifications made directly to the PagingFiles registry entry take effect only after restarting the computer, as the Windows Memory Manager initializes virtual memory allocation during the early stages of the system boot sequence.