Screen Glitches, Goes Black And Hard Drive Stops Spinning

the screen glitches with pink, white, and green tiles and lines, the cursor disappears, the screen goes black, and the hard drive stops spinning. All the lights on the front of the computer stay on, the fans stay on, and the monitor doesn't say anything about not receiving a signal. The first time it happened I tried turning it on right away and it booted up and let me sign in, but as it was loading the desktop and icons it glitched again, and froze. after I shut down and let it sit for a while it worked just fine until the next day when it did the same thing again, but twice in one day and with a shorter time between freezes. Today I had a WerFault.exe error pop up and when I clicked ok on it the bottom half of my screen turned pinkish and the computer froze when I restarted the pink tone was still there but it did not show up on any windows that I opened and when the background changed it went away.