Question Frequent Pc crashes

[jessicat1261]

Pc keeps crashing randomly,applied thermal paste to the cpu and gpu,still crashes,so it's not that,i have also cleaned my pc components so that's not the issue either.I am thinking it's my psu or gpu,but i'm not much of a technical expert.My specs are:
Windows 10 Home 64-bit
Cpu (Intel Core i5 3330)
8GB ram
Psu (Intergrator 500W)
MoBo (MSI H61M-P31/W8)
GPU (Nividea Geforce GTX 760)
240GB SSD & 1863GB HDD

(My SSD still has 147GB left and my HDD still has 1.74TB left)
(PC was given to me as a gift a year ago,so i don't know if it's prebuilt or not)

Thank you!

 

[rgd1101]

(My SSD & HDD is nowhere near full)

and how full is nowhere near full on the ssd?

test with a better psu?

 

[jessicat1261]

and how full is nowhere near full on the ssd?

test with a better psu?

My SSD still has 147GB left and my HDD still has 1.74TB left,And yes i am thinking it might be the psu,but i don't want to waste money just in case it isn't.