Windows 8 is freezing in weird ways or lagging at random times.

Windows 8 is freezing in weird ways or lagging at random times but I can always move the mouse around on the screen. I can't get the shut-down/restart options to show up. I can't get folders to open up. The screen saver won't start. But I can use the web browser to access the internet. Just all online video is laggy and choppy. This weird lagging and freezing doesn't happen as soon as the computer is turned on. It takes 30 minutes before everything starts to run slow and act weird. When it's restarted or turned on for the first time, everything runs fine for about 30 minutes. After that, things start to happen. I've scanned it multiple times with Malwarebytes & Norton but nothing wrong comes up in the scans. My computer is only a year old and I hardly have any programs on it. I reformatted it multiple times recently. Or as close to reformatting as I can get. Windows 8 did not come on disk with my computer but instead it was set up on a separate partition on my hard drive. So whenever I want to "reformat", I hit the F2 button during restarting until it takes me to the one step recovery screen and I go from there to set up windows from the factory partition. Afterwards, all of my programs and files are deleted and the computer is restored to it's factory released state. And even after I've restored it to this point many times, windows is STILL slowing down and freezing. This just started happening out of nowhere in the last 2 weeks. I am CLUELESS as to what is wrong and I'm losing my mind trying to figure it out. Is there anything anybody can suggest for me to maybe fix it? My One year warrenty just expired so I'm on my own right now with fixing it cuz I am too broke to take it in to be fixed professionally. I am hoping somebody awesome here will be able to walk me through some kind of process that can find the problem and hopefully fix it.


Thank you so much for reading this!! I appreciate any advice!!!

I have a Lenovo H520
System Model 10094
Windows 8.0 64 Bit
Intel Core i5-3330 CPU @ 3.00GHz
8192 MB RAM