My System:

Hi guys any help will be great.
I have a packard bell utow-ori currently when I turn on the pc the red light on the front flashes and then goes out the blue led flashes and then nothing happens.
Could this be the psu which is a 250w?

I have a HP Pavilion 7806 which has a 250 w PSU however the dimensions are different this works when I put the power lead into it.
Could i swap the psu's even though the dimensions are different.
I am an absolute novice at this stuff as you might have guessed any thoughts would be great.

Thanks Jared