can you please send me a note of your system build.
motherboard , make n modle,
ram make and modle,
graphics card make and modle,
PSU - wattage and make.
and a list of all your peripheral attached devices.
please view your event log and check for errors
[right click on my computer;
then select manage;
then choose event viewer.
Browse through the various options and see if their are reocurring errors, look at the time intervals and determine if they are equal, if they are it is a software issue. If errors are not equal we will need to take a logical approach to ascertain the root cause.