Should I add a tag to a question after the answer indicates that something, identified by the tag, is related with the question? [duplicate]

Question

For example, if someone asks this question:

I'm getting an error doing X. Why?

A possible answer could be:

You need to do Y to avoid getting this error.

If Y is a technique or tool and if Y has a tag, should I edit the question to add the y tag? It seems correct because specialists in y will be able to find the question and add more useful information.

However, I can see two issues:

1. If a or b is also a possible solution, the question will have many distinct tags.

Example

Question:

My PC is freezing. What should I do?

Answer 1:

You need to run an anti-virus to remove malwares.

Answer 2:

Your PC may be overheated. Check if your fan is working correctly.

So, in this case, should I add anti-virus + cooling to the question?

2. If the question is marked with y, the OP will look a bit dumb for asking something that is quite obvious if you see the tag.

Example

Question:

What series is it?

Answer:

This is "Game of Thrones".

Adding a game-of-thrones tag would make the OP to look dumb.

Another example for this would be:

Question:

How can I securely store an user password?

Answer:

You should hash the password before storing it.

In this case, should I add the hash tag?

So, how should I proceed? Is there a generic guidance?