Microsoft Hyper-V VHDPMEM BTT Filter (bttflt) Service Defaults in Windows 11
Default Settings
| Startup type: | Manual |
| Display name: | Microsoft Hyper-V VHDPMEM BTT Filter |
| Service name: | bttflt |
| Service type: | kernel |
| Error control: | normal |
| Group: | PnP Filter |
| Path: | %SystemRoot%\System32\drivers\bttflt.sys |
| Registry key: | HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\bttflt |
Default Behavior
Microsoft Hyper-V VHDPMEM BTT Filter is a kernel driver. In Windows 11 it starts only if the user, an application or another service starts it. If Microsoft Hyper-V VHDPMEM BTT Filter fails to start, the failure details will be recorded into Event Log. Then Windows 11 should boot up and notify the user about the bttflt service startup failure.
Restore Default Startup Configuration of Microsoft Hyper-V VHDPMEM BTT Filter
1. Run the Command Prompt as an administrator.
2. Copy the command below, paste it into the command window and press ENTER:
sc config bttflt start= demand
3. Close the command window and restart the computer.
The bttflt service is using the bttflt.sys file that is located in the C:\Windows\System32\drivers directory. If the file is removed or corrupted, read this article to restore its original version from Windows 11 installation media.