CPU upgrade help

[Spiders]

I recently upgraded my cpu from an e2140 to an e6300, when I tried to boot windows it would just continuesly restart, by all means the CPU and BIOS where supposedly supported, and the BIOS did show the e6300 installed. but i recently found out my psu is only 300w with a 20pin connector, my mobo can use 24pins, could this be the issue why it wont boot? my graphics card required 550w but is running off the 300w psu, (though it is always underclocked, and now I know why)

my psu is ATX-300w p4-12v

 

[Spiders]

Im hoping its the psu, but could it be the mobo? I only have enough money to replace one

 

[Spiders]

Guess no one knows

 

[dividebyzero]

Sorry....
But as you've already suspected, you'll be needing a new power supply.
When you have the funds look for a power supply that is at least ATX 2.0 standard (24 pin motherboard connector).
If you supply your system details (mainly graphics card and any add-in cards (i.e. tv tuner/soundcard) someone here will be able to recommend a solid choice for you.