Similar problem here, except on WinXP. Updated windows a couple of hours ago and can't start Warband now, ntdll.dll error. And no info in rgl_log.txt.
Verifying the cache in steam caused it to redownload the intro (and reset the launcher settings), which it now plays before crashing with the same ntdll.dll error message.
Edit: Thanks, but I've already been through various ntdll.dll pages already (including ones on this forum). :p Only change today from when I've been happily plodding along in Pendor the last weeks is the windows update earlier today, so I'll put my money on that.