please dont rip this site Prev Next

WM_COMPACTING Overview  Group

The WM_COMPACTING message is sent to all top-level windows when Windows detects more than 12.5 percent of system time over a 30- to 60-second interval is being spent compacting memory. This indicates that system memory is low.


wCompactRatio = wParam; // compacting ratio 



Value of wParam. Specifies the ratio of central processing unit (CPU) time currently spent by Windows compacting memory to CPU time currently spent by Windows performing other operations. For example, 0x8000 represents 50 percent of CPU time spent compacting memory.

Return Values

If an application processes this message, it should return zero.


When an application receives this message, it should free as much memory as possible, taking into account the current level of activity of the application and the total number of applications running with Windows.

file: /Techref/os/win/api/win32/mess/src/msg22_18.htm, 1KB, , updated: 2000/4/7 11:20, local time: 2023/12/5 13:16,

 ©2023 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE!


After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type a nice message (short messages are blocked as spam) in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.

Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?


Welcome to!


Welcome to!