kennethspradlin397 :
my specs for my computer that I bought..... an AMD eight-core FX 8320 vishera processor 3.5ghz turboed at 4.0ghz 8mb cache a 1tb hard drive and an AMD Radeon RX 460 2 GB graphics card
He wants to know your existing PSU's capacity and model number. That will likely be written on the side of the PSU. If you can't see it through the window in the case, you can take off the case's side panel (preferably when powered down) and see if you can see it then.
Also, it would be helpful to know how much you were considering spending on a graphics card upgrade. To see noticeably improved performance over an RX 460, you would probably want to move up to at least a GTX 1060.
Lutfij :
I know but suggesting a higher wattage PSU is for longevity's sake with other factors in mind(like overclocking and higher ambient/operating temps). If we're all going by with bare minimum's then expect to see troubleshooting+headaches and later dry wallet syndrome when you have to buy a new PSU.
Yeah, if you're buying a PSU that might be worth keeping in mind, but it's more than likely alright to keep the existing PSU unless it happens to be of especially poor quality or low wattage. The PSU included in one of these pre-built systems probably won't be great, but if it's a 400+ watt model it would likely be fine enough to run anything up to a GTX 1060, at least.