WHERE and HAVING are fundamentally different; they should never be thought of as equivalent or interchangeable. That is, for a given query/subquery, only one of them is right to use.

Use WHERE when you want to filter individual row values.

Use HAVING when you want to filter based on aggregate/group values.

SQL Server used to allow non-aggregate column names in the HAVING clause, and indeed then did not evaluate that condition until after GROUPing had been done; from SQL 2005 on, I don't SQL even allows that any more.