My pc is acting up

[Andrew_A98]

So I built my second pc about a month ago. The only things that were not brand new were the HDD and SSD. I put everything together and it was all fine up until my pc said my windows was not active. I ended up doing a clean install of windows and everything was working fine. For maybe a week. Now suddenly my pc randomly resets then says that boot device is not detected. Not only that but it would constantly lag and would be slow when I used it. Eventually I got frustrated so I did yet another reset of my computer and it worked maybe for 2 days before windows updated and the same problem is occuring. I just did another reset and it's still slow as usual? Anyone know what it is? I did the windows sfc /scannow and it says no problems detected. Could it be a bad SSD since that's what I have my os on? Also every now and then my keyboard and mouse won't respond to anything I click or type and when it does it takes a bit of time for me to see a response. Please help. I need it badly and haven't been able to fix the problem

 

[CountMike]

I would do a serious check of that and other drives (if applicable). Only than you can say for sure if it's drive or SW/OS problem.