Who knows computer stuff?

my computer goes into sleep mode when i leave it on too long. When i go to start it up in the morning, it lags so bad the mouse barley moves and it takes like 10min to press restart. I unplug the internet and it helps a bit. But after it restarts its totally fine? Iv had a fatal error screen pop up before but it just restarts itself and its fine.

I did buy a new graphics card not long ago. Could that be something?