I have a similar startup problem. It started when I downloaded the latest nVidia drivers and installed them (v53.03). After discovering the startup delay and removing the new graphics drivers (to no avail), I started a long, long process of uninstalling different software & downgrading/removing drivers in an attempt to discover what was causing this. I assumed it was a conflict between my graphics card drivers (Leadtek A310 TD FX5600) & other software, drivers etc but I eventually took the plunge & re-installed XP. The result is that I am no further forward and the startup delay still exists (so defragging the HD etc etc is absolutely no use whatsoever).

For the moment I have decided to live with it as I don't reboot or power down the PC on a regular basis (as Taiwan says, other than a slow start the pc runs perfectly). I suppose it's one of those Windows niggles we have all grown used to over the years and until I stumble over the solution either on the net or by myself, I'll just have to put up with it.