My problem is exactly as the subject reads, oddly enough!

When I turn on my PC from cold it boots as far as the animated bar. The
screen will flash briefly after a few seconds and the hard disk light will
stop.

Usually, after I press the reset button, Vista will boot. Sometimes it
takes two or three resets.

I thought it might be my USB memory stick but I remove that and the same
thing happens.

I also tried creating ntbtlog.txt but it's nowhere to be found on my system.

Anyone have any idea what's happening?

Many thanks.