Serious problem need help

[zaxix]

hey guys i really need help my pc wont stay on when i boot up

my pc set up is

abit IS-10 mobo

intel pentium 4 HT CPU 3.0GHz

G-Skull 1GB memory

power color ati raidon 2600XT 512MB agp gfx card

creative sound card

modem

CD-R drive

lite-on DVD-RW DL Drive

just a note i haven't been on it for about a week before then it worked perfect

i will boot up the pc to windows and it will go into windows but when i click on a file the pc just reboots then i will only the to the boot screen then the screen starts to dim

if i remove the modem sound and gfx cards the pc works fine

and the pc will not let me even try to format the hard drive

so if anyone can help me i whould be vary greatfull

 

[jsrudd]

Could be the power supply then. Will it work if you just remove one of those cards or must all three be removed? And what do you mean the PC won't let you try and reformat the hard drive?

 

[zaxix]

when i try to format the hard drive with the XP cd it will come to a blue screen then reboot the pc

if i remove the gfx card the other cards wont work it wont notice thos cards are there
everything is mostly new in the pc except for the cd-r and hard drive power supply its 400W psu