Pc wont post after failed overclock

I am a newbie in overclocking, and I just got a new pc, so I thought I would start overclocking on my old pc just to get the hang of it, on my old gigabyte p35 motherboard using easy tune 5, I foolishly just raised the clock of processor 300 mhz and clicked GO button,

the computer shut down and it wont post anymore absolutely nothing on the screen, what astonishes me though is that the motherboard seems to be working, I heard the beeping of the motherboard and the fans running and everything good but no post, my first doubt offcourse is that the problem is with the processor,

but just to make sure everything else is running, I tested my GPU(9500 gt) on another board and it isnt working, I tested a new GPU on the p35 board thinking that maybe the bad part is the GPU but to no avail, it wont work either.

does that mean that both processor and my 9500 gt are gone, how can that even happen?

my old build is:
processor: dual core e5300 2.5 ghz
VGA: 9500 GT
PSU: no brand 500 watt
hard: western digital 500 gb