Dream Machine

[originunknown]

Ok this is weird and scary ... I have Vista premium and password protected page at open. This morning when I booted up the puter the password page had a logo I never saw before which I found strange even though it had the same texture and design as my regular logos. The real shocker was when my password did not work!!! After trying three times and denying me access the machine just rebooted and I was back with my regular logo and the password worked. Should I be worried and what should I do if anything?

Thanks!

ps the registry on this machine is still screwed with periodic blue screens that fix themselves with a reboot and I have been using the same password for 3 years plus.

Help!