I did the Win7 SP1 upgrade yesterday on my laptop.

While was installing the SP1 suddenly a blue screen appeared saying about a problem that you encounter for the first time and your system must reboot.

After rebooting, I got a message that SP1 was successfully installed!!!

Brilliant! Only Microsooft knows. Thumbs up from them for the n-th time. (you bloody piece of s**t, you destroyed the world...)