Q: Why does my system hang at the Windows screen after flashing the BIOS from newer version to an older one? [TH7II/TH7II-RAID]
A: Because the latest BIOS 38 for TH7-II board has added some revised I/O Mapping from previous versions. Therefore, if you flash the BIOS from the newer version (38) to older one (37), it will corrupt your operating system.
We suggest you do not downgrade to an older BIOS unless you have backups.