I need some help to fix Windows update error that I am facing regularly. I hope there are people who will be willing to fix this up. I have Windows Vista Ultimate. When I try to run Windows update I receive a error saying that Windows cannot find update. The error code is 80070490 and it stopped by popping up a message that Windows Update has faced unknown error. I had tried some basic steps to fix the issue out. I had first stopped windows service and then deleted the folder SoftwareDistribution from C:\Windows. It will be auto generated on reboot.