First, to be totally certain we should get the system information. You can just run either one of these free programs to get your system information. HWinfo64 is more complete, CPU-Z is easier to understand.
https://www.hwinfo.com/download.php
https://www.cpuid.com/softwares/cpu-z.html
Also, open up your case and look at your Power Supply Unit (PSU), there should be a label on it that states the wattage. If you are unsure, just take a picture and post it. I am particularly interested in the the number of amperes (A) on the +12V circuit (rail). I suspect that it will be a budget 300W.
http://www.tomshardware.com/faq/id-1927916/power-supply-101-understanding-power-supplies-selecting-job.html...