Sometimes during boot-up (there's no pattern that I can make out) Windows XP will get stuck at the blue 'Welcome' screen. If I press Esc or Enter then Windows continues to boot up and everything is fine, any other key and it just sits there. It's like there's a dialogue box hidden behind the blue.
Has anyone encountered this before or knows what it might be?
Edit: Just been thinking again about ChrisF's reply. While I don't have any thumbdrives, etc attached I do use a Microsoft Wireless Keyboard and Mouse. This thing loves to tell me that its batteries are running low (sometimes as early as five minutes after a replacement) by popping up a dialogue box. Is this likely to be the cause?