Windows 10 PIN entry problem.

Hey all,
I have an older DELL T3500 desktop that I occassionally use. It has a problem with PIN entry on start up. It starts as normal but when I try and enter a PIN the keyboard doesn't enter any letters. It will enter numbers without problem. At first I thought a keyboard problem but I have been prompted to enter A1, B2, C3 on a couple of occassions and it does this just fine. WIFI mouse and Keboard and the mouse is just fine. I've done a few restarts but nothing changes. A wifi keyboard from another desktop which works fine does the same thing on the T3500 (enters numbers but not letters).
Incidentally, the on-screen keyboard does exactly the same thing.
Would appreciate any suggestions about solving this problem.
Regards,
Bill

dalchina said:

When you created the PIN, did you opt to include letters- i.e. does your PIN (Personal Identity NUMBER) actually consist of numbers only or numbers and letters?

Add PIN to your Account in Windows 10
Option 1, 4 - tick box 1st screenshot

If numbers only, letters will not be accepted.

Good grief, feeling silly now. I must be losing it. The moment I looked at your posted forum link and saw mention of "Hello" it clicked. As I said, I seldom use that computer and it is the only one of five with the "Hello" PIN needed. I did not even notice it was asking for a PIN and not a windows logon password.
Many thanks for hepling me out.
Regards,
Bill