My mom uses her laptop all day every day for her small business. It's a Dell that's a couple years old and lately she's been complaining about performance. I did the regular basic maintenance: blow out the vents, malware check and defrag. There were a couple infections, nothing that's too damaging and the fragmentation was pretty bad so I left it to defrag overnight and told her that is going to be better tomorrow.

Next time I'm over she's got the same complaints so I do a Malware check again with 0 results, fragmentation is low. Mom mentions that the laptop gets hot but it's an i7 with a slim profile case so I don't pay much mind to the heat because I think that it's too be expected. I spend half an hour browsing the internet just to get a feel for the laptop and the fan starts going crazy pretty soon, I prop the laptop up so that the bottom vents are getting air and still the fan is going 100%. At this point I shut down the laptop and popped the bottom open and everything seemed in order: nothing loose, vents and radiators are dust free. Next step: take off the heatsink. Once I took off the heatsink I saw the problem right away: the compound was very dry, flaky and worn away. Ordered new compound on Amazon and the laptop was working like new the next day.

I feel that manufacturers may use this trick of using low longevity thermal compound (the stuff they used wasn't your typical compound, from the looks of it I gathered that it comes in pre-cut rectangles and it had a foamy feel to it) as one way of planned obsolescence. I can just see many people out there just buying new laptops (this conversation originally started with my mom asking me advice on new laptops) when they start having these issues and the virus check and defrag don't help anymore.

Moral of the story: when in a support role always get to the bottom of the users motives, there might be and easier and/or cheaper solution.

P.S. laptops are likely to share a single heatsink between the GPU, CPU and a few smaller chips so the cumulative performance drop is crippling. Also make sure to put new compound on all of the chips that connect to the heatsink and clean them off with high grade isopropyl alcohol first.