CPU clock speed stuck at 0.80Ghz after windows 10 update.

[Max_Pare]

My friend owns a dell laptop with a i7 6700hq, the pc never had issues running programs or doing simple actions, it has an hssd wich lets him open programs lightning fast without a problem, but since the most recent Windows 10 update, his cpu clock has been locked to a maximum of 0.8Ghz, even if all the battery saving settings are set to maximum performance. The last update has been giving problems to litterally every person that i know that has windows 10 pc, me included. Since this major update (that took hours to install) our pcs are extremely slow and simple actions like opening folders have become slow and sluggish, it's like our pcs turned into 10 years old pcs out of nowhere. I did manage to fix my issue by setting the max and minimum paging memory to the reccomended amount, wich seems to fix the issue with a lot of users, but my friends still have this issue even after doing that. All of them have an original version of windows 10 home that came with their pre-assembled pc or laptop.

 

[Rdslw]

you can disable C states in bios, but battery life on laptop will suffer a lot.
this thread might be helpfull

https://communities.intel.com/thread/97358

also check please if its in bios locked or if it locks after a period of time. There was a problem with returning from one of C states and disabling just this one is simplest and cleanest solution for time beeing.

 

[Max_Pare]

you can disable C states in bios, but battery life on laptop will suffer a lot.
this thread might be helpfull

https://communities.intel.com/thread/97358

also check please if its in bios locked or if it locks after a period of time. There was a problem with returning from one of C states and disabling just this one is simplest and cleanest solution for time beeing.

We tried resetting bios to default just in case but nothing seems to have changed, and it's a work laptop so the charger is plugged in 90% of the time anyways.
What confuses me is that this was not a problem before this windows update, and correct me if i'm wrong but OS updates don't even touch the bios settings, nor would they update the bios since they are completely separate things, and by experience i know that you need to take a physical storage like an usb and flash the new bios update directly on the motherboard.
And thank you, i will let him know (i wrote this for him simply because he doesn't really speak english).