Windows XP Home SP2 Boot Problem

Hi everyone

I have a shop built desktop PC with the following specs

Graphic Card Nvidia GEForce 7900 GT

AMD Athlon 64 Processor 3500+
2.21 Ghz
1GB RAM

It is connected to a SAMSUNG 40? TV via VAG cable

WHen it boots up it goes as far as the windows boot screen (with the blue moving bar), after a few seconds the screen goes blank and the TV reads no signal. It sounds like the computer continues to boot but with no image.

I can boot in SAFE MODE but everything looks fine there.

I have repair upgarde of Windows with no problems, the monitor continued to work through thr whole install period

My first thoughts were that it was the graphic card but I am not sure, any ideas?

Thanks in adavnce.

JOhn