Most Vista machines are still under warranty. Call it in so you won't pay for this one.
Not sure if this is the best part of the forum to post this but just today I switched on my computer (running Vista H.Premium) and it appeared to get stuck on the screen with the green loading bar that goes across with Microsoft Corporation written beneath it. The bar was still going across but nothing was loading. On some other forum sites I found that the problem could be something related to the HDD having major problems. I eventually had to manually switch off the computer and then booted it back up again. When I was prompted I chose the option to start Windows normally. This time it booted fine.
Is this a sign that my hard drive is beginning to fail? Or was it just a random windows typical failure? The computer is only about 1 year old and I only installed sp1 about a week ago.