系统默认会在 C:\Windows 目录下创建 MEMORY.DMP 文件，来搜集内存错误信息。但有时却找不到。搜索后找到原因：系统分区剩余空间小于25G会自动删除该文件。 

Algorithm to decide whether to store/delete memory.dmp file generated after a system crash:

1. First report the kernel fault to the Online Crash Analysis Service.
2. Then, if machine has a registry setting AlwaysKeepMemoryDump set to 1, store the dump file on disk.
3. Else, if machine is a Windows Server SKU, store the dump file on disk.
4. Else, if the machine is joined to a domain (i.e. this is a corporate machine), store the dump file on disk.
5. Else, if machine is not on a domain (i.e. this is a home user’s machine),
   • If free disk space is >= 25GB, store the dump file on disk.
   • Else (free disk space is < 25 GB), delete the dump file.

（http://blogs.msdn.com/b/wer/archive/2009/02/09/kernel-dump-storage-and-clean-up-behavior-in-windows-7.aspx）

如若始终保存该文件，须在注册表中添加相应键值：

The exact location of the AlwaysKeepMemoryDump setting in the registry is:

• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CrashControl\AlwaysKeepMemoryDump Type: REG_DWORD