I downloaded it using Windows Update. Then,it told me it had to restart the PC. It did. Then the installation resumed. I went away for a few minutes and when I came back, a session of disk error check was scheduled and was running. Now, all I see is a black screen with the following: "!!0xc0190036!! 1316/68500 (mmcss.dll)" PLEASE SOMEONE HELP

Hello and welcome to PC Help Forum.

I cannot find anything specific on that error code,could you please check it is correct.

Can you get into safe mode by rebooting PC/Laptop and repeatedly tapping F8,then try uninstall SP1 from there.

Microsoft are offering free support for Vista SP1 problems. You can either email them or chat live to someone from Microsoft to get help with your problem. See link below:

https://support.microsoft.com/oas/de...4&gprid=500921

Thanks for the link... I actually rebooted the system, started Startup Repair and ran System Restore before installing SP1... the PC is fine now.
But I would like to install it... So I don't want this error to happen again... (and by the way, I'm not new here lol)
Yes, the error code is correct. i checked it on another discussion forum, people have had the exact same problem

I would wait for the final release.