Ntfs - ntfs.sys - NTFS filesystem driver For stubborn tags, attach the Windows 7 kernel debugger ( kd.exe from the WDK) and use !poolused or !findpool commands. This is advanced but definitive. Part 5: Common Leaky Tags on Windows 7 (Real-World Examples) | Tag | Likely Driver | Typical Cause | |-----|---------------|----------------| | MmSt | Memory Manager | Superfetch or memory mapped file leak | | CM31 | Configuration Manager | Registry hive not being unmapped | | Thre | Kernel Threads | Driver creating threads without cleaning up | | Ntfr | NTFS Filter Drivers | Antivirus or backup filter driver | | FMfn | File System Runtime | Network redirector (e.g., WebDAV) | | Perf | Performance Counters | Faulty performance DLL |
findstr /m /l "TagName" C:\Windows\System32\drivers\*.sys Replace TagName with the 4-character tag (e.g., Ntfs ). This searches all driver binaries for that string. Often, the tag is embedded near the driver’s allocation routines. Microsoft provides pooltag.txt – a mapping file. On a WDK-installed system, find it at: C:\WinDDK\7600.16385.1\tools\other\pooltag.txt poolmon.exe download windows 7
Navigate to where poolmon.exe lives, or add that folder to your PATH environment variable. Then type: Ntfs - ntfs
Download the Sysinternals Suite (easiest) or the WDK 7.1.0 (most official). Run poolmon -b -d regularly. And when you see that one tag ballooning to gigabytes of non-paged pool, you’ll know exactly which driver to blame. Disclaimer: Windows 7 reached end of life on January 14, 2020. Microsoft no longer provides security updates. Use PoolMon and diagnostic tools only on systems that are isolated from the internet or as part of a controlled migration plan. This searches all driver binaries for that string
For Windows 7 users, especially those dealing with mysterious system slowdowns, "low memory" warnings despite having ample RAM, or driver-induced crashes (BSODs), PoolMon is an indispensable scalpel. While Windows 7 is no longer under mainstream Microsoft support, millions of legacy systems, industrial machines, and personal computers still run it. Understanding how to obtain and use PoolMon on this OS remains a critical skill.
Introduction: What is PoolMon.exe? In the realm of Windows system administration and advanced troubleshooting, few tools are as revered—and as misunderstood—as PoolMon.exe (Pool Monitor). This command-line utility, part of the Windows Driver Kit (WDK), provides a real-time, bird’s-eye view of the Windows kernel memory pools: Paged Pool and Non-Paged Pool .