VB script not working

I have used the script below in other spreadsheets to convert text to all caps as the user inputs data but, for some reason, it's not working. Am I doing something wrong? I got this script off the internet and it has worked for me for a year. I am not educated in VB so please dumb down the responses for me, please! thanks!

Private Sub Worksheet_Change(ByVal Target As Range)
Dim actionRange As Range
Dim oneCell As Range

Set actionRange = Range("b3:ABC5000"): Rem adjust

Set actionRange = Application.Intersect(Target, actionRange)
If Not actionRange Is Nothing Then
On Error GoTo ErrorHalt
Application.EnableEvents = False

For Each oneCell In actionRange
oneCell.Value = UCase(oneCell.Value)
Next oneCell

End If
ErrorHalt:
Err.Clear
Application.EnableEvents = True
End Sub

I tested it in a blank spreadsheet and it worked fine. Your range is set to B:3, so anything before cell B:3 wont be converted to all caps, everything after will. Where did you paste the code? I pasted it into Sheet1.

Yes, it is in Sheet 1. I don't need anyting in rows 1 or 2 or in column A converted as I have those cells locked and I have the sheet protected. Could that be the reason why it's not working?

It could be that the sheet is protected. If I protect my sheet, it wont work at all, in fact I get a message saying I need to unprotect sheet before I can make changes.

Well, I must have really hosed something up. It won't work if I unprotect it either. And I tried in a blank spreadsheet like you did and couldn't get it to work there, either. Ugh. Thanks for your help though!