Audio and Video Problems when starting a video

Hello,
I finished at my wits with this issue and hope that someone will facilitate American state out. For the past 3 or four weeks, this is often the matter that has been occurring. Sometimes my screen can go back, it says 'no signal' as if it were unplugged from the PC.
The sound conjointly extends on one bit for a couple of seconds then cuts out. The PC remains on although and therefore, the power light-weight doesn't pulse as if it were in sleep mode. I've noticed this downside happens most frequently whereas taking part in a video that has to lead American state to believe it is the graphics card. However, with the sound downside also I am unsure what it's.
What I accustomed to do was simply the power it off manually and begin it duplicate, and it might be fine for to a small degree where else. However, it has been happening. Therefore, often times I simply do not watch videos on my PC any longer. My PC may be an entryway DX4200-09, Quad core Processor, 4GB RAM and 640GB drive. The video card was bought one by one.
It's AN NVIDIA GeForce 9400 GT. My package is Windows seven. If I am forgetting any specs that may be useful to please let American state understand. I hope somebody out. There will facilitate American state figure this out I might rather simply replace the video card if that's the matter instead of bring it into a geek squad or one thing to work this out.
Thanks in advanced for any help!
