|Don't necessarily assume this must be a software fault. |
Bad RAM can cause issues for example. If the RAM is accessible take it out and clean its edge connectors with a pencil eraser, then pop the sticks in and out a few time to clear any oxide off the sockets. Do the same with any add-on cards including video card.
Check that all the internal connectors are firmly home.
I'm assuming it is a tower and accept that the above can be more tricky with a laptop.
Always pop back and let us know the outcome - thanks