this are causing several day after day.
I am confused now Where to go how to recover.
Sounds like the motherboard may be going bad, or you have bad memory, or you have a bad power supply.
You can take the typical debugging steps. I would first try different memory. Then, I would try a different power supply.
If that does not work, I would take a trip to the recycle facility.
The "recycle facility" is a worst case scenario. If your board is bad/failed/broken, that is the proper way to dispose of it.
Then other case is to take the board to a computer repair shop.
Well, you can try un-install on board LAN driver, and then re-boot, it will re-install the driver itself , or you may need install the driver manually. I belive the driver files are corrupted in some point.
On the other hand, it could be a sign of your mechanical hard drive start to fail. You can use "Crystal Disk Info" (a free tool) to scan the status for your hard drive, if it prompts you a warning sign, you're better backup your data ASAP before any disaster happened.
For testing the system memory, you can try MemTest86 (it has free version) .
There are many reasons why system running slow. it's hard to said what causes those problems.
Oh, for the screen strange problem, it could be display card has problem. Try un-install driver reboot computer and re-install it. If the problem still exist, it's likely display card has hardware problem, maybe memory chips goes bad. You need replace the display card. If you using onboard display, it maybe system memory goes bad, but it's hard to say.