Intermittent black screen then shutdown

Hi any advice, Ive looked for hours for answers. My screen keeps intermittently going black - for about 10 seconds then comes on again. Sometimes goes black and I have to shutdown.
We are graphic designers ( not too techy ) so often have a lot of graphics open. But it happens with nothing open too and getting more frequent.

ANy advice ?

 

Sounds like it may be a failing video card. Or possibly overheating. Test with another video card if you can.

 

If not the video card it could be the harddrive.You can buy one cheap at newegg.com and install windows cd and remove old harddrive and see if that solves your problem $45.00 total cost.I recently had a hard drive failing that took 8 weeks before it totally died.What are the computer specs and when do you get the black screen start up apps???

Could also be your power supply or a bad connection