Hallo !I have a little Problem.I dont can install Updates for Defender. "Code: 80070539"And my english is not so good. Thanks

If System Restore is also failing, you probably have some form of Malware running. I would go to MalwareBytes.orgRating posts helps other users Mark L. Ferguson MS-MVP

I think that site is malware : PThe truth is I go back to win98se because I don't have to take my computer onto the internet at all. But sites are like people, they have distinctive features.

80070539 ERROR_INVALID_SIDThe security ID structure is invalid.What is the installed antivirus/security suite and does it include an antispyware component ? MowGreen MVP Data Center Management - Update Services Consumer Security

Have you installed an antivirus program yourself? I havent noticed anything called anti-virus in windows 7, just the defender balloon "look for anti-virus on line." (something I would not reccommend) I have a Norton Disk ready for that.

To whom are you addressing that question to ? If you're asking me, what does that have to do with the Original Poster's issue ? There are AVs available for Win7. Installing older versions of them is not recommended.MS has this page ... Windows 7 Security ProvidersAvast works well with Win7, but is not on the above page. Caveat emptor for any Norton product. MowGreen MVP Data Center Management - Update Services Consumer Security