I've just tried twice to install Win7 Service Pack 1 on a relative's Acer desktop PC - which runs ZoneAlarm anti-virus, but has very little else apart from Word installed. Each time, the download and install process seemed to go OK; however, when the system rebooted, it displayed the Windows startup logo, but at the point where the logo goes away and you expect to see the mouse appear, it just froze with a blank grey screen. I left it for a while, but nothing happened. Eventually, I power-cycled the PC and an error message was displayed and a Windows boot selection was offered: Repair (recommended) or Start Normally. Choosing 'Start Normally' repeated the boot and freeze sequence. Choosing 'Repair' started the startup repair procedure, which failed with 'The operating System is incompatible with Startup Repair'. Trying the 'Advanced Restore' procedure reported 'No restore points', although I had explicitly created one before the update, and the update itself creates one. I managed to fix it by running 'Startup Repair from the original Windows 7 installation DVD. The PC works fine now, but Service Pack 1 isn't installed. I have had to turn off automatic updates so that it won't get installed. Does anyone know what the problem might be, or suggestions for a fix? Failing that, is there a way to disable the 'Service Pack 1' entry in 'Windows Updates' so that automatic updates can be enabled?