PC wont boot - help

[liner33]

I have a Dell XPS PC running Win 8.1. I've been having various issues of late but now if it boots up ok it runs for a short period and then freezes making a horrible noise through the speakers, I have to hold down the power button to switch it off , when I try to reboot the power light flashes off and on but it wont boot.

I have a green LED on the back under the power supply and the yellow led on the motherboard stays lit ok

I've made sure everything is plugged in securely but now out of ideas

[liner33]

Done the dust and clean out and general check over

The pc is about 2 years old , not under warranty I fitted a SSD last year and installed Win 8 on that

Does it sound plausible that the power supply is failing and when my graphics card demand increases the power supply cant supply enough power therefore we get a freeze?

[liner33]

well got it running with the intergrated graphics , does this mean my graphics card or power supply are goosed ?

I have a fairly decent GeForce graphics card but its been running fine with the power supply for two years, maybe i should upgrade both ?