Glad you got it sorted! I use the HP as a test machine for software and I had the same issue...I found a few solutions
Causes
1. Dust
2. Windows update (For some reason when it runs, the fan goes mental)
3. Run from admin powershell or cmd powercfg /energy
Note | Powercfg will run a quick test and spit out a report for you, of all the various energy issues it has detected. It won't fix them, but the report will provide enough information to troubleshoot with lots of help from Google
Solutions
1. Remove back and clean dust or your tried and proven method of the vacuum
Note | I would caution that using a household vacuum may have unintended consequences. Dust if left uncleaned clings together becoming large enough to catch itself on the circuitry and as it gets vacuumed out may dislodge or damage critical components. It always best to remove the back casing and only clean the fan, plus it will allow you to thoroughly clean it
2. Chill pad or some other external cooling surface for it to rest on helps.
3. Now the strange one, that I can't explain. Install Intel's extreme tuning utility (XTU) its a free overclocking tool. You may already be familiar with it, but for some reason it seems to regulate heat once installed. Plus, it will provide you detailed information with regard to temp and allow you to overclock the CPU, if you wish....
4. Intel provides two other drivers that may or may not be pre-installed but worth updating as they help considerably cool the PC
a) Intel ® Dynamic Platform and Thermal Framework (Intel® DPTF)
b) Intel Collaborative Processor Performance Control (CPPC)
Note| Both help manage and extend access your access to settings that control power/energy consumption. The reason I prefaced the last solution with ..'depending on what you use it for'...is because with installing Intel XTU and have access to the CPU and GPU tweaking options, both these drivers may not give a gamer that 100 degree burn on the CPU, as they limit this level of overheating. Again with XTU you can play a balancing act overriding those limitations
Note_2 | If you are a Gamer, which I'm not....that 100 degree burn either means you need to upgrade your system to suit your needs. As the CPU should be sub 70 degrees majority of the time and only breaching that for short bursts which the CPU regulates. There are many registry tweaks that can be done to get you the same performance as you get with 100 degree burn i.e. increase worker threads. Also, the two main reasons for that 100 degree burn are
a) GPU configuration - its not being used on all graphics tasks that its designed for...but note GPU will never perform all of the graphics related tasks...some will still be done by CPU...but if you overheating then its more than likely the GPU is far less than it share
b) DISK I/O caching that is built into windows is very conservative,,,and if you test disk i/o speed on your SSD you'll see what I mean. Its barely scratching the surface of what the SSD is capable of and this is why the CPU is overheating. Its cache write happens far more frequently than it needs to as its buffer is too small. I would explore using a third party caching software i.e. Primo cache or a ram disk.. You can also tweak the cache directly, by using a free tool from Windows Sysinternals called cacheset.....but those settings don't carryover to a reboot so you'll need to set it each session and it won't give you the same blistering speed as using a third party caching software
Hope that helps someone...I know this is a late reply to an old thread. I still have the HP as experimental unit, but I've moved from HP...I've had too many issues with them over the years. For me Asus laptops are first class, followed by Dell