0x00000041: How to Fix MUST_SUCCEED_POOL_EMPTY Error
0x00000041 usually means MUST_SUCCEED_POOL_EMPTY. Officially, the bug check value is 0x00000041, and it indicates that a kernel-mode thread requested too much must-succeed pool; no driver is permitted to request must-succeed pool, and Windows issues this bug check if that request cannot be filled. (Microsoft Learn)
The fastest safe first step is to sort the crash into one of three patterns: after a recent driver change, during startup or shutdown, or after dump analysis points to broader pool pressure.
What does 0x00000041 mean in Windows?
It is a Windows blue-screen stop code, not a normal app popup, and it points to a kernel-mode driver path that needs dump analysis and driver-focused troubleshooting.
MUST_SUCCEED_POOL_EMPTY in plain English
The label attached to this stop code is MUST_SUCCEED_POOL_EMPTY. A reported example from bleepingcomputer.com shows STOP: 0x00000041 … MUST_SUCCEED_POOL_EMPTY. (hashroot.com)
For troubleshooting, the practical takeaway is to identify the driver involved and then replace, remove, update, or rewrite that driver. Microsoft says the kb stack backtrace command should be used first and can show the driver that caused the error. (source)
Why this differs from an app error with the same code
Pages about installer, network, or app errors that reuse 0x00000041 are describing a different problem space. On a BSOD, the key evidence is the dump file and the driver stack.
According to Bug Check 0x41 MUST_SUCCEED_POOL_EMPTY — Microsoft identifies the bug check value as 0x00000041. (source)
What should I do first when I get stop code 0x00000041?
Start with pattern matching, not repair scans. If the first crash followed a driver change, open Device Manager, find the device you changed, then use Properties > Driver > Roll Back Driver. If rollback is not available, use Update Driver or restore the system to a point before the first crash. If you have a dump file, inspect it before swapping drivers at random.
Three-path triage table
| Symptom pattern | Likely next check | Fastest safe check | Next action |
|---|---|---|---|
| BSOD appears during startup, shutdown, resume, or just before the sign-in screen | Check whether a recent driver or firmware change happened before the first crash | Disable Fast Startup at Control Panel > Hardware and Sound > Power Options > Choose what the power buttons do > Change settings that are currently unavailable > clear Turn on fast startup | Check the BIOS or UEFI version shown in System Information (msinfo32) against the version on the system maker’s support page, then review recently changed drivers |
| Crashes begin right after a new driver, dock, SSD tool, GPU package, antivirus filter, or motherboard utility | Recent system-level driver change | Open Device Manager > the changed device > Properties > Driver > Roll Back Driver, or use Update Driver for the recently changed device | If rollback is unclear, open Control Panel > Recovery > Open System Restore, click Next, pick a restore point dated before the first BSOD, and then confirm the faulting stack in WinDbg with kb |
| Minidumps keep naming different modules, or kb does not cleanly point to one bad actor | Use the Microsoft debugger commands for pool analysis | Open the dump in WinDbg, run kb first, then !vm 1 to view total pool usage, then !poolused 2 for per-tag nonpaged pool usage | If pool usage is abnormal, add !poolused 4 for per-tag paged pool usage and trace the dominant tag or repeated stack owner back to the related driver package |
Likely causes, ranked by fit
A recent driver change is an important first check because it is easy to verify and reverse. If no clear change lines up with the first crash, move to dump analysis with kb, !vm 1, and the pool-usage commands rather than guessing from timing alone.
What do the bug check parameters for 0x00000041 mean?
The supplied Microsoft documentation for this bug check does not define the meanings of parameters 1 through 4. Instead of trying to decode those values from an unsupported table, use the documented debugger flow: kb first, then !vm 1, then !poolused 2, and !poolused 4 if needed.
Read the values as a pressure snapshot
You can still record the four values from the blue screen or dump header as part of the crash record, but do not treat them as a reliable driver ID on their own. For this stop code, Microsoft’s documented path is stack backtrace first and pool-usage inspection after that.
If the same stop code appears repeatedly, compare the dumps for timing, repeated modules in the backtrace, and repeated pool tags rather than relying on the raw parameter values alone.
