The word "had" is used when we formulate sentences using the present perfect tense plus a past participle.
So, for example, "They have fixed laptops for a few months now." This implies that whatever they started doing is still ongoing.
But, we can easily change it to mean something that once occurred in the past, but didn't necessarily continue well into the future/present time.
"They had fixed laptops."
This indicates that they once did something, but it doesn't indicate that they kept up with fixing laptops.
"He has (has and have are both a part of the present perfect) Dan help him fix his laptop."
"He had Dan help him fix his laptop."
Hope this was helpful!
Note: I completely interpreted this the wrong way. My apologies! The answer below is a good answer! :)