After installing Preview Build 9926 the user may face problems in sign in to Windows with PIN.
Why it is happening?
In Windows 10 Technical Preview build 9926 this behaviour till now is normal. There may be a myriad of issues-the previous PIN may not be preserved, sometimes you may be able to sign in but you can’t change the settings, even PIN doesn’t show up as a sign in option on the logon screen.
The PIN infrastructure for Windows 10 has been changed entirely what we have observed a simple 4-digit substitution for your password in Windows 8.1. So it is still under construction as far as Windows 10 Technical Preview build 9926 is concerned. Microsoft’s Windows Team is working on it to fix this issue.