Laptop its suddenly slow in every aspect and I've done everything trying to fix it

[CarlosReyes]

My laptop has been acting weird for the last 5 days. I'ts so slow at startup and peformance in general that it's freaking me out. I've done every single thing the HP support assintant has told me to. but it still haven't fixed it yet. Yes I have enough RAM, GPU and everything. Yes my air vents are very clean. Also there's this error that shows up every time I turn on my laptop a DLL error that couldn't find a module or something like that I really dont know if it has something to do with the problem that Im having.

some of the processes or thing that I have alredy trying to fix it are. Disk cleanup, Updating BIOS, Scan all my files, something like kinda renovating some files I think it was called SFC, also I've tried disk defragmentation. when I tell you I've done everything the assistant has told me its because I have. this is my last resource since I'm no longer in warranty for online assistance so I would really appreciate If you could give me some possible solutions.

[WAWood]

@CarlosReyes 

That file error generally means that the windows filesystem has become corrupted causing the OS to not be able to read a specific file anymore.

This issue is often due to a failing drive. So, let's check that first, because if it is failing, it would need to be replaced and there is no point then in doing anything else until we confirm that.

If your PC is new enough to support UEFI, you can use these steps to test the hard drive: http://support.hp.com/us-en/document/c00439024

If not, to check the drive you have to follow these steps:
1) Press Esc key repeatedly, several times a second, while rebooting the laptop. Do NOT hold the key down, just press it over and over.
2) Eventually, you will see an HP Startup Menu
3) Press the Function key for testing the hard drive (usually F2) and let it run.