As shown in the screenshot attachment, when using the exFAT file system as the system volume to run the latest version of Windows 11 Build 27686, the following bugs exist:
1. When the Shim DataBase file exists, the system UWP such as the start menu and settings cannot be opened. If you delete the file named "RandomGUID.sysmain.sdb" in the "C:\Windows\apppatch\MergeSdbFilesSource" directory, or delete the registry "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\SdbUpdates" item, the problem can be solved. This bug has existed since Win11 v22H2 two years ago and has not been fixed yet.
2. When the Smart App Control function is in the evaluation or enabled state, the operating system will run very slowly. If you set it to off in app & browser control in Windows Security, or directly change the "VerifiedAndReputablePolicyState" key value in the registry "HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\CI\Policy" to "0" to turn it off, the problem can be solved. This bug has existed since Win11 v22H2 two years ago and has not been fixed yet.
3. Check Disk Utility will throw an error when checking exFAT volumes with a total number of clusters between 2^30 and 2^32 (that is, the FAT table size is between 4GB and 16GB), but in fact the volume is completely normal and not damaged. In addition, according to the exFAT file system specification, a single exFAT volume can have a maximum of 4294967295 allocation units, which means that the maximum partition capacity supported by formatting with 4KB clusters is 4096Byte 2^32Byte=16TB. However, when trying to load a volume of this size, it takes a long time to complete the operation, which may be another bug.
4. The change partition size function in the disks & volumes in the new system storage settings will cause file system corruption and loss of all data when operating on exFAT volumes. If the volume is a system partition, it will immediately trigger BSOD and cause the OS to completely crash and fail to start. This is a very dangerous bug.
5. When the system Blue Screen of Death occurs, the DUMP file cannot be generated normally in the exFAT volume. This seems to be a bug in exfat.sys.
6. When the system volume is exFAT, the hiberfil.sys file cannot be created normally, resulting in the inability to use the hybrid boot function. The 0xc0000010 error will also be prompted through command line operations. This seems to be a bug in exfat.sys.
7. Every time try to run a user UWP app such as Microsoft Store, the AppX Deployment Service will repeatedly stop abnormally, causing the UWP program to crash immediately. This seems to be a bug in AppXDeploymentServer.dll.
Please fix these bugs, thanks!
In addition, it usually takes a long time to boot Windows in the exFAT volume. Can you optimize the boot speed of exFAT system volumes in OS Loader?
Note:
If you want to use exFAT as the Windows system volume, you need to use NTFS to complete the system installation first, then restart and enter Windows PE to open CMD.exe and execute the following command to capture the .WIM image file:
Dism /Capture-Image /ImageFile:D:\Backup.wim /CaptureDir:C:\ /Name:Backup
After capturing the .WIM image, execute the following command to format the system volume C:\ to the exFAT file system:
Format C: /FS:exFAT /Q /A:4096 /Y
After formatting, execute the following command to apply the .WIM image file:
Dism /Apply-Image /ImageFile:D:\Backup.wim /Index:1 /ApplyDir:C:\
After the .WIM image is applied, restart and finally the system will boot from the exFAT volume.
