New system shutting off automaticaly

[PhntmKLR]

1st off thanks to any one that can help.
ok....
Just built a new PC, this is my 2nd PC build so i do have some experience
but the problem i am having is totally new to me.

Pc specs.

amd socket A 3200+
Abit KW7 mobo
thermaltake 430watt PS
Geforce 6600GT
1.5 Gig of RAM

here is the problem

PC will start and then automatically shut off after about 1 1/2 minutes this time does not fluctuate much always about 1 1/2 minutes after restarting.
Cannot turn system back on untill I use the switch on the PowerSupply.

CPU temp according to Bios is 42degC

 

[PhntmKLR]

Well i have seemed to solve the problem. After doing some reading I took off the heatsink cleaned off the cpu and heatsink reapplied thermal grease and Ive now been running for about 8 hours straight. Hope this may help someone else in the future.

 

[Megatron]

I was just about to say. Your problem was over-heating hands down.