No Video Display After Random Crash

i cannot find any information on across the internet.things to know:

-i am using an acer aspire m3802 on a windows 7 os
-750gb storage space
-4gb ram
-i use an nvidia geforce gt 230 graphics card
-both disc drives are nearly full
-i have recently installed two video editing programmes (30 day trials)
-for about half a year my computer has had minor glitches when playing Internet videos or music

so i was on the surfing the internet and my monitor suddenly goes completely black. the fan was still going and the lights were still on, but i couldn't interract with the computer because i had no display whatsoever. about an hour beforehand i had been converting some hd video files, which was probably using up a lot of memory, and i had been skyping too. the computer had been running a lot more slowly over the past couple of days, but had shown no signs of being about to break. so i turned the computer off and then tried to reboot it. the acer logo appeared, but after that nothing else happened, not even the 'start windows normally' screen. the mouse still lit up and the computer seemed to be alive, but it downright refused to display anything at all. when i briefly tilted it, however, the display popped up for another millisecond. i tried rebooting this morning, at which point the 'acer' screen briefly flashed up. i managed to start it up in 'safe mode' and the core features of the computer appear to be working. however, when i tried to access the internet, the error '0x80131018' appeared. (this may be completely irrelevant but every piece of information helps!) so we can basically rule out that the monitor is playing up, which makes me wonder how far inside the computer the problem is hidden.